3Com 3.01.01 User Manual

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Switch 8800 Configuration Guide

Version 3.01.01

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Published February 2005 Part No.10014298

3Com Corporation 350 Campus Drive Marlborough, MA 01752-3064

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CONTENTS

ABOUT THIS GUIDE

Conventions 1

SYSTEM ACCESS

Product Overview 3

Function Features 3 Configuring the Switch 8800 4 Setting Terminal Parameters 5

Configuring Through Telnet 7

Configuring Through a Dial-up Modem 10

Configuring the User Interface 11 Command Line Interface 19

Command Line View 19

Features and Functions of the Command Line 22

PORT CONFIGURATION

Ethernet Port Overview 27

Configuring Ethernet Ports 27

Example: Configuring the Default VLAN ID of the Trunk Port 34

Troubleshooting VLAN Port Configuration 34 Configuring Link Aggregation 34

Load Sharing 35

Port State 36

Configuring Link Aggregation 36

Example: Link Aggregation Configuration 38

VLAN CONFIGURATION

VLAN Overview 39 Configuring VLANs 39

Common VLAN Configuration Tasks 39

Adding Ethernet Ports to a VLAN 40 Configuring GARP/GVRP 42

Configuring GVRP 44

NETWORK PROTOCOL OPERATION

Configuring IP Address 49

Subnet and Mask 50 Configuring an IP Address 50 Troubleshooting an IP Address Configuration 52

Configuring Address Resolution Protocol (ARP) 52

Configuring ARP 52

DHCP Relay 54

Configuring DHCP Relay 55 Troubleshooting a DHCP Relay Configuration 58

IP Performance 59

Configuring TCP Attributes 59 Displaying and Debugging IP Performance 59 Troubleshooting IP Performance 60

IPX Configuration 61

IPX Address Structure 61 Routing Information Protocol 61 Service Advertising Protocol 61

IP ROUTING PROTOCOL OPERATION

IP Routing Protocol Overview 63

Selecting Routes Through the Routing Table 64 Routing Management Policy 65

Static Routes 67

Configuring Static Routes 68 Troubleshooting Static Routes 71

RIP 71

Configuring RIP 72 Troubleshooting RIP 81

OSPF 81

Calculating OSPF Routes 81 Configuring OSPF 84 Troubleshooting OSPF 103

IS-IS 105

Two-Level Structure of IS-IS 105 NSAP Structure of IS-IS 107 IS-IS Packets 108 Configuring Integrated IS-IS 109 Integrated IS-IS Configuration Example 123

BGP 125

BGP Messages 126 BGP Routing 126 BGP Peers and Peer Groups 127 Configuring BGP 127 Typical BGP Configuration Examples 145 Troubleshooting BGP 151

IP Routing Policy 151

Routing Information Filters 152

Configuring an IP Routing Policy 153

Troubleshooting Routing Policies 159 Route Capacity 159

Limiting Route Capacity 160

Configuring Route Capacity 160

MULTICAST PROTOCOL

IP Multicast Overview 167

Multicast Addresses 168

IP Multicast Protocols 170

Forwarding IP Multicast Packets 171

Applying Multicast 172 Configuring Common Multicast 172

Configuring Common Multicast 172 Configuring IGMP 174

Configuring IGMP 175 IGMP Snooping 181

Configuring IGMP Snooping 184

IGMP Snooping Configuration Example 186

Troubleshooting IGMP Snooping 186 Configuring PIM-DM 187

Configuring PIM-DM 188

PIM-DM Configuration Example 191 Configuring PIM-SM 192

PIM-SM Operating Principles 193

Preparing to Configure PIM-SM 194

Configuring PIM-SM 195 GMRP 203

Configuring GMRP 204

QOS/ACL OPERATION

ACL Overview 207

ACLs Activated Directly on Hardware 207

ACLs Referenced by Upper-level Modules 207

ACLs Supported 208 Configuring ACLs 208

Configuring Time Range 209

Defining and Applying a Flow Template 209

Defining ACLs 211

Activating ACLs 212 Displaying and Debugging ACL Configurations 213 ACL Configuration Example 213

Basic ACL Configuration Example 214

L2 ACL Configuration Example 215

QoS Configuration 216

QoS Configuration 219

Configuration Examples 229

Traffic Policing Configuration Example 229 Traffic Shaping Configuration Example 231 Port Mirroring Configuration Example 231 Traffic Priority Configuration Example 232 Traffic Redirection Configuration Example 233 Queue Scheduling Configuration Example 234 WRED Parameters Configuration Example 235 Traffic Statistics Configuration Example 235

Configuring Logon User ACL Control 236

Configuring ACL for Telnet Users 236 Configuration Example 237 Configuring ACL for SNMP Users 238 Configuration Example 239

STP OPERATION

STP Overview 241 Configuring STP 241

Designating Switches and Ports 242 Calculating the STP Algorithm 242 Generating the Configuration BPDU 243 Selecting the Optimum Configuration BPDU 243 Designating the Root Port 243 Configuring the BPDU Forwarding Mechanism 245

MSTP Overview 246

MSTP Concepts 246 MSTP Principles 249

Configuring MSTP 249

Configuring the MST Region for a Switch 250 Specifying the Switch as Primary or Secondary Root Switch 251 Configuring the MSTP Operating Mode 252 Configuring the Bridge Priority for a Switch 253 Configuring the Max Hops in an MST Region 253 Configuring the Switching Network Diameter 254 Configuring the Time Parameters of a Switch 255 Configuring the Max Transmission Speed on a Port 256 Configuring a Port as an Edge Port 257 Configuring the Path Cost of a Port 257 Configuring the Priority of a Port 259 Configuring the Port Connection with the Point-to-Point Link 260 Configuring the mCheck Variable of a Port 261 Configuring the Switch Security Function 262 Enabling MSTP on the Device 263 Enabling or Disabling MSTP on a Port 263 Displaying and Debugging MSTP 264

AAA AND RADIUS OPERATION

IEEE 802.1x 265

802.1x System Architecture 265

Configuring 802.1x 267 Configuring the AAA and RADIUS Protocols 274

Configuring AAA 276

Configuring the RADIUS Protocol 279

Troubleshooting AAA and RADIUS 289

RELIABILITY

VRRP Overview 291 Configuring VRRP 292

Enable Pinging the Virtual IP Address 292

Setting Correspondence Between Virtual IP and MAC Addresses 293

Adding and Deleting a Virtual IP Address 293

Configuring the Priority of Switches 294

Configuring Preemption and Delay for a Switch 294

Configuring Authentication Type and Authentication Key 295

Configuring the VRRP Timer 295

Configuring a Switch to Track an Interface 296

Displaying and Debugging VRRP 296

Troubleshooting VRRP 299

SYSTEM MANAGEMENT

File System 301

Using a Directory 301

Managing Files 302

Formatting Storage Devices 302

Setting the Prompt Mode of the File System 302

Configuring File Management 303

FTP 304

TFTP 306 Managing the MAC Address Table 307

Configuring the MAC Address Table 308 Managing Devices 312

Rebooting the Switch 8800 312

Designating the File for the Next Boot 312

Displaying Devices 313 Maintaining and Debugging the System 313

Configuring System Basics 314

Displaying System Information and State 315

Debugging the System 315

Testing Tools for Network Connection 317

Logging Function 318 SNMP 322

SNMP Versions and Supported MIB 322 Configuring SNMP 323

RMON 329

Configuring RMON 330

NTP 333

Configuring NTP 335 NTP Configuration Examples 341

ABOUT THIS GUIDE

This guide describes the 3Com® Switch 8800 and how to configure it in version

3.0 of the software.

Conventions Ta bl e 1 lists icon conventions that are used throughout this book.

Ta bl e 1 Notice Icons

Icon Notice Type Description

Information note

Information that describes important features or instructions.

Caution Information that alerts you to potential loss of data

Warning Information that alerts you to potential personal

or potential damage to an application, system, or device.

injury.

Ta bl e 2 lists the text conventions used in this book.

Ta bl e 2 Text Conventions

Convention Description

Screen displays This typeface represents information as

Keyboard key names If you must press two or more keys

Press Ctrl+Alt+Del The words “enter” and type”

When you see the word “enter” in this guide, you must type something, and then press Return or Enter. Do not press Return or Enter when an instruction simply says “type.”

Italics are used to: Emphasize a point.

Denote a new term at the place where it is defined in the text.

Identify menu names, menu commands, and software button names. Examples:

Click OK. Words in bold

Boldface type is used to highlight command names. For example, “Use the display user-interface command to...”

it appears on the screen.

simultaneously, the key names are linked with a plus sign (+), for example:

Words in italics

Identify command variables.

From the Help menu, select Contents.

2 ABOUT THIS GUIDE

SYSTEM ACCESS

This chapter covers the following topics:

■ Product Overview

■ Configuring the Switch 8800

■ Setting Terminal Parameters

■ Command Line Interface

Product Overview The 3Com Switch 8800 is a large capacity, modular wire speed Layer 2/Layer 3

switch. It is designed for IP metropolitan area networks (MAN), large-sized enterprise networks, and campus network users.

The Switch 8800 has an integrated chassis structure. The chassis contains a I/O module area, fan area, power supply area, and a power distribution area. In the I/O module area, there are seven, ten, or fourteen slots. Two slots are reserved for the switch Fabric modules, and the remaining slots are for the I/O modules. You can install different interface modules for different networks; the slots support a mixed set of modules.

The Switch 8800 supports the following services:

■ MAN, enterprise/campus networking

■ Multicast service and multicast routing functions and support audio and video

multicast service.

Function Features Ta bl e 1 lists and describes the function features that the Switch 8800 supports.

Ta bl e 1 Function Features

Features Support

VLAN VLANs compliant with IEEE 802.1Q standard

STP protocol Spanning Tree Protocol (STP)

Flow control IEEE 802.3x flow control (full-duplex)

Broadcast suppression Broadcast suppression

Multicast GARP Multicast Registration Protocol (GMRP)

Port-based VLAN GARP VLAN Registration Protocol (GVRP)

Rapid Spanning Tree Protocol (RSTP) Multiple Spanning Tree Protocol (MSTP), compliant with IEEE

802.1D/IEEE 802.1s Standard

Back-pressure based flow control (half-duplex)

Internet Group Management Protocol (IGMP) Snooping Internet Group Management Protocol (IGMP) Protocol-Independent Multicast-Dense Mode (PIM-DM) Protocol-Independent Multicast-Sparse Mode (PIM-SM)

4 CHAPTER 1: SYSTEM ACCESS

Console port

Table 1 Function Features (continued)

Features Support

IP routing Static route

RIP v1/v2 OSPF BGP (in advanced software) IS-IS (in advanced software) IP routing policy

DHCP Relay Dynamic Host Configuration Protocol (DHCP) Relay

Link aggregation IEEE 802.3ad Link aggregation

Mirror Port-based mirroring (one to one, many to one)

Security features Multi-level user management and password protect

Reliability Virtual Redundancy Routing Protocol (VRRP)

Quality of Service (QoS) Traffic classification

Management and maintenance

Loading and updating Loading and upgrading software using the XModem protocol

802.1X authentication Radius authentication Packet filtering

Bandwidth control Priority Queues of different priority on the port Queue scheduling: supports strict priority (SP), weighted round robin (WRR), committed access route (CAR) queueing

Command line interface configuration Configuration through the console and AUX ports Local or remote configuration by Telnet Remote configuration by dialing the modem through the AUX port SNMP System log Level alarms Output of the debugging information PING and Tracert Remote maintenance with Telnet and modem

Loading and upgrading software using the File Transfer Protocol (FTP) and Trivial File Transfer Protocol (TFTP)

Configuring the Switch 8800

On the Switch 8800, you can set up the configuration environment through the console port. To set up the local configuration environment:

1 Plug the DB-9 or DB-25 female plug of the console cable into the serial port of the

PC or the terminal where the switch is to be configured.

2 Connect the RJ-45 connector of the console cable to the console port of the

switch, as shown in

Figure 1 Setting Up the Local Configuration Environment Through the Console Port

Figure 1.

RS-232 Serial port

Console cable

Setting Terminal Parameters 5

Setting Terminal Parameters

To set terminal parameters:

1 Start the PC and select Start > Programs > Accessories > Communications >

HyperTerminal.

2 The HyperTerminal window displays the Connection Description dialog box, as

shown in

Figure 2 Set Up the New Connection

Figure 2.

3 Enter the name of the new connection in the Name field and click OK. The dialog

box, shown in

Figure 3 displays.

4 Select the serial port to be used from the Connect using dropdown menu.

Figure 3 Properties Dialog Box

6 CHAPTER 1: SYSTEM ACCESS

5 Click OK. The Port Settings tab, shown in Figure 4, displays and you can set serial

port parameters. Set the following parameters:

■ Baud rate = 9600

■ Databit = 8

■ Parity check = none

■ Stopbit = 1

■ Flow control = none

Figure 4 Set Communication Parameters

6 Click OK. The HyperTerminal dialogue box displays, as shown in Figure 5.

7 Select Properties.

Figure 5 HyperTerminal Window

Setting Terminal Parameters 7

8 In the Properties dialog box, select the Settings tab, as shown in Figure 6.

9 Select VT100 in the Emulation dropdown menu.

10 Click OK.

Figure 6 Settings Tab

Configuring Through

Te ln e t

Setting the Terminal Parameters is described in the following sections:

■ Configuring Through Telnet

■ Configuring Through a Dial-up Modem

■ Configuring the User Interface

Before you can telnet to a Switch 8800 and configure it, you must:

1 Configure the IP address of a VLAN interface for the Switch 8800 through the

console port (using the ip address command in VLAN interface view)

2 Add the port (that connects to a terminal) to this VLAN (using the port command

in VLAN view)

3 Log in to the Switch 8800

Tasks for Configuring through Telnet are described in the following sections:

■ Connecting the PC to the Switch 8800

■ Connecting Two Switch 8800 Systems

8 CHAPTER 1: SYSTEM ACCESS

1 Authenticate the Telnet user through the console port before the user logs in by

2 Enter system view, return to user view by pressing Ctrl+Z.

3 To set up the configuration environment, connect the Ethernet port of the PC to

Connecting the PC to the Switch 8800

To connect the PC and Switch 8800 through Telnet:

Te ln e t.

By default, a password is required for authenticating the Telnet user to log in the Switch 8800. If a user logs in by Telnet without a password, the user sees the message:

<SW8800>system-view [SW8800]user-interface vty 0 4 [SW8800-ui-vty0]set authentication password simple/cipher xxxx

(xxxx is the preset login password of Telnet user)

that of the Switch 8800 through the LAN. See

Figure 7 Setting Up the Configuration Environment Through Telnet

Figure 7.

Workstation

Switch 8800 Ethernet port

Ethernet

WorkstationServer

4 Run Telnet on the PC by selecting Start > Run from the Windows desktop and

entering Teln et in the Open field, as shown in

Figure 8 Run Telnet

PC (for configuring the switch through Telnet)

Figure 8. Click OK.

The terminal displays User Access Verification and prompts you for the logon password.

5 Enter the password. The terminal displays the command line prompt (<SW8800>).

If the message, Too many users! appears, try to reconnect later. At most, 5 Telnet users are allowed to log on to a Switch 8800 simultaneously.

Setting Terminal Parameters 9

6 Use the appropriate commands to configure the Switch 8800 or to monitor the

operational state. Enter

? to get immediate help. For details on specific

commands, refer to the chapters in this guide.

When configuring the Switch 8800 by Telnet, do not modify the IP address unless necessary, because the modification might terminate the Telnet connection. By default, after passing the password authentication and logging on, a Telnet user can access the commands at login level 0.

Connecting Two Switch 8800 Systems

Before you can telnet the Switch 8800 to another Switch 8800, as shown in Figure 9, you must:

1 Configure the IP address of a VLAN interface for the Switch 8800 through the

console port (using the ip address command in VLAN interface view)

2 Add the port (that connects to a terminal) to this VLAN (using the port command

in VLAN view)

3 Log in to the Switch 8800

After you telnet to a Switch 8800, you can run the telnet command to log in and configure another Switch 8800.

Figure 9 Provide Telnet Client Service

Telnet client

Telnet server

1 Authenticate the Telnet user through the console port on the Telnet Server (Switch

8800) before login.

By default, a password is required for authenticating the Telnet user to log in the Switch 8800. If a user logs into Telnet without password, the system displays the following message:

2 Enter system view, return to user view by pressing Ctrl+Z.

<SW8800>system-view [SW8800]user-interface vty 0 [SW8800-ui-vty0]set authentication password simple/cipher xxxx (xxxx is the preset login password of Telnet user)

3 Log in to the Telnet client (Switch 8800). For the login process, see “Connecting

the PC to the Switch 8800”.

4 Perform the following operations on the Telnet client:

<SW8800>telnet xxxx

(XXXX can be the hostname or IP address of the Telnet Server. If it is the hostname, you need to use the ip host command to specify it).

5 Enter the preset login password. The Switch 8800 prompt (<SW8800>) displays. If

the message,

Too many users! displays, try to connect later.

10 CHAPTER 1: SYSTEM ACCESS

6 Use the appropriate commands to configure the Switch 8800 or view its

operational state. Enter

? to get immediate help. For details on a specific

command, refer to the appropriate chapter in this guide.

Configuring Through a

Dial-up Modem

To configure your router with a dial-up modem through the AUX port:

1 Authenticate the modem user through the console port of the Switch 8800 before

the user logs in to the switch through a dial-up modem.

By default, a password is required for authenticating the modem user to log in to the Switch 8800. If a user logs in through the modem without a password, the user sees the message,

Password required, but none set.

a Enter system view, return user view with Ctrl+Z.

<SW8800>system-view [SW8800]user-interface aux 0 [SW8800-ui-aux0]set authentication password simple/cipher xxxx (xxxx is the preset login password of the Modem user.)

b Using the modem command, you can configure the console port to modem

mode.

[SW8800-ui-aux0]modem

2 To set up the remote configuration environment, connect the modems to a PC (or

a terminal) serial port and to the Switch 8800 console port, as shown in

Set Up

Remote Configuration Environment.

Figure 10 Set Up Remote Configuration Environment

Modem serial port line

Modem

Telephone line

PST

Console port

Modem Remote telephone: 555-5555

3 Dial for a connection to the switch, using the terminal emulator and modem on

the remote end. Dial the telephone number of the modem connected to the Switch 8800. See

Figure 11 and Figure 12.

Figure 11 Set the Dialed Number

Setting Terminal Parameters 11

Figure 12 Dial the Remote PC

4 Enter the preset login password on the remote terminal emulator and wait for the

<SW8800>prompt.

5 Use the appropriate commands to configure the Switch 8800 or view its

operational state. Enter

? to get immediate help. For details on a specific

command, refer to the appropriate chapter in this guide.

Configuring the User

Interface

By default, after login, a modem user can access the commands at Level 0.

User interface configuration is another way to configure and manage port data.

The Switch 8800 supports the following configuration methods:

■ Local configuration through the console port

■ Remote configuration through Telnet on the Ethernet port

12 CHAPTER 1: SYSTEM ACCESS

■ Remote configuration through a modem through the console port.

There are two types of user interfaces:

■ AUX user interface is used to log in the Switch 8800 through a dial-up modem.

A Switch 8800 can only have one AUX port.

■ VTY user interface is used to telnet the Switch 8800.

For the Switch 8800, the AUX port and Console port are the same port. There is only the type of AUX user interface.

The user interface is numbered by absolute number or relative number.

To number the user interface by absolute number:

■ The AUX user interface is the first interface — user interface 0.

■ The VTY is numbered after the AUX user interface. The absolute number of the

first VTY is the AUX user interface number plus 1.

To number the user interface by relative number, represented by interface + number assigned to each type of user interface:

■ AUX user interface = AUX 0.

■ The first VTY interface = VTY 0, the second one = VTY 1, and so on.

Tasks for configuring the user interface are described in the following sections:

■ Entering the User Interface View

■ Configuring the Attributes of the AUX (Console) Port

■ Configuring the Terminal Attributes

■ Managing Users

■ Configuring the Attributes of a Modem

■ Configuring Redirection

■ Displaying and Debugging User Interface

Entering the User Interface View

Use the user-interface command (see Tab le 2) to enter a user interface view. You can enter a single user interface view or multi-user interface view to configure one or more user interfaces.

Perform the following configuration in system view.

Ta bl e 2 Enter User Interface View

Operation Command

Enter a single user interface view or multi user interface views

user-interface [ type ] first-number [ last-number ]

Configuring the Attributes of the AUX (Console) Port

Use the speed, flow control, parity, stop bit, and data bit commands (see Ta bl e 3) to configure these attributes of the AUX (Console) port.

Setting Terminal Parameters 13

Perform the following configurations in user interface (AUX user interface only) view.

Ta bl e 3 Configure the Attributes of the AUX (Console) Port

Operation Command

Configure the transmission speed on AUX (Console) port. By default, the transmission speed is 9600bps

Restore the default transmission speed on AUX (Console) port

Configure the flow control on AUX (Console) port. By default, no flow control is performed on the AUX (Console) port

Restore the default flow control mode on AUX (Console) port

Configure parity mode on the AUX (Console) port. By default, there is no parity bit on the AUX (Console) port

Restore the default parity mode undo parity

Configure the stop bit of AUX (Console) port. By default, AUX (Console) port supports 1 stop bit

Restore the default stop bit of AUX (Console) port

Configure the data bit of AUX (Console) port. By default, AUX (Console) port supports 8 data bits.

Restore the default data bit of AUX (Console) port

speed speed-value

undo speed

flow-control { hardware | none | software }

undo flow-control

parity { even | mark | none | odd | space }

stopbits { 1 | 1.5 | 2 }

undo stopbits

databits { 7 | 8 }

undo databits

Configuring the Terminal Attributes

The following commands can be used for configuring the terminal attributes, including enabling/disabling terminal service, disconnection upon timeout, lockable user interface, configuring terminal screen length and history command buffer size.

Perform the following configuration in user interface view. Perform the lock command in user view.

Enabling and Disabling Terminal Service After the terminal service is disabled on a user interface, you cannot log in to the Switch 8800 through the user interface. However, if a user logged in through the user interface before disabling the terminal service, the user can continue operation. After the user logs out, the user cannot log in again. In this case, the user can log in to the Switch through the user interface only when the terminal service is enabled again. Use the commands described in

Ta bl e 4 Enabling and Disabling Terminal Service

Operation Command

Enable terminal service shell

Disable terminal service undo shell

Ta bl e 4 to enable or disable terminal service.

14 CHAPTER 1: SYSTEM ACCESS

By default, terminal service is enabled on all the user interfaces.

Note the following points:

■ For the sake of security, the undo shell command can only be used on the user

interfaces other than the AUX user interface.

■ You cannot use this command on the user interface through which you log in.

■ You must confirm your privilege before using the undo shell command in any

legal user interface.

Configuring idle-timeout By default, idle-timeout is enabled and set to 10 minutes on all the user interfaces. The idle-timeout command is described in Ta bl e 5.

Ta bl e 5 Idle Timeout

Operation Command

Configure idle-timeout idle-timeout minutes [ seconds ]

(idle-timeout 0 means disabling idle-timeout.)

Restore the default idle-timeout undo idle-timeout

Locking the User Interface The lock command locks the current user interface and prompts the user to enter a password. This makes it impossible for others to operate in the interface after the user leaves. The lock command is described in Ta bl e 6.

Ta bl e 6 Lock User Interface

Operation Command

Lock user interface lock

Setting the Screen Length If a command displays more than one screen of information, you can use the screen length command to determine how many lines are displayed on a screen so that information can be separated in different screens and you can view it more conveniently. The screen-length command is described in

Ta bl e 7 Setting Screen Length

Operation Command

Set the screen length screen-length screen-length (screen-length

Restore the default screen length undo screen-length

Ta bl e 7.

0 indicates to disable screen display separation function.)

By default, the terminal screen length is 24 lines.

Setting the History-Command Buffer Size

Ta bl e 8 describes the history-command max-size command.

By default, the size of the history-command max-size command buffer is 10.

Ta bl e 8 Set the History Command Buffer Size

Operation Command

Set the history command buffer size history-command max-size value

Setting Terminal Parameters 15

Table 8 Set the History Command Buffer Size

Operation Command

Restore the default history command buffer size

undo history-command max-size

Managing Users

The management of users includes, the setting of the user logon authentication method, the level of command a user can use after logging on, the level of command a user can use after logging on from the specific user interface, and the command level.

Configuring the Authentication Method The authentication-mode command configures the user login authentication method that allows access to an unauthorized user.

Ta bl e 9 describes the authentication-mode command.

Perform the following configuration in user interface view.

Ta bl e 9 Configure Authentication Method

Operation Command

Configure the authentication method authentication-mode { password | scheme

}

Configure no authentication authentication-mode none

By default, terminal authentication is not required for users who log in through the console port, whereas a password is required for authenticating modem and Telnet users when they log in.

To configure authentication for modem and Telnet users:

1 Configure local password authentication for the user interface.

When you set the password authentication mode, you must also configure a login password to log in successfully.

Ta bl e 10 describes the set authentication

password command.

Perform the following configuration in user interface view.

Ta bl e 10 Configure the Local Authentication Password

Operation Command

Configure the local authentication password set authentication password { cipher |

Remove the local authentication password undo set authentication password

simple } password

Configure for password authentication when a user logs in through a VTY 0 user interface and set the password to 3Com:

[SW8800]user-interface vty 0 [SW8800-ui-vty0]authentication-mode password [SW8800-ui-vty0]set authentication password simple 3Com

2 Configure the local or remote authentication username and password.

Use the authentication-mode scheme command to perform local or remote authentication of username and password. The type of the authentication depends on your configuration. For detailed information, see

“AAA and RADIUS

Operation”

16 CHAPTER 1: SYSTEM ACCESS

3 Set the Switch 8800 to allow user access without authentication.

Perform username and password authentication when a user logs in through the VTY 0 user interface and set the username and password to zbr and 3Com respectively:

[SW8800-ui-vty0]authentication-mode scheme [SW8800-ui-vty0]quit [SW8800]local-user zbr [SW8800-luser-zbr]service-type telnet [SW8800-luser-zbr]password simple 3Com

[SW8800-ui-vty0]authentication-mode none

By default, the password is required for authenticating the modem and Telnet users when they log in. If the password has not been set, when a user logs in, the following message displays,

If the authentication-mode none command is used, the modem and Telnet users are not required to enter a password.

Set the Command Level after Login The following command is used for setting the command level used after a user logs in.

Perform the following configuration in local-user view.

Ta bl e 11 Set Command Level Used After a User Logs In

Operation Command

Set the command level used after a user logging in

Restore the default command level used after a user logging in

service-type { level level | telnet [ level level ] ] | telnet [ level level ] }

undo service-type { level | telnet [ level ] ] | telnet [ level ] }

By default, a Telnet user can access the commands at Level 1 after logon.

Setting the Command Level Used after a User Logs in from a User Interface

Use the user privilege level command to set the command level, after a user logs in from a specific user interface, so that a user is able to execute the commands at that command level.

Ta bl e 12 describes the user privilege level

command.

Perform the following configuration in user interface view.

Ta bl e 12 Set Command Level After User Login

Operation Command

Set command level used after a user logging in from a user interface

Restore the default command level used after a user logging in from a user interface

user privilege level level

undo user privilege level

By default, a user can access the commands at Level 3 after logging in through the AUX user interface, and the commands at Level 0 after logging in through the VTY user interface.

Setting Terminal Parameters 17

When a user logs in to the switch, the command level that the user can access depends on two points. One is the command level that the user can access, the other is the set command level of the user interface. If the two levels are different, the former is taken. For example, the command level of VTY 0 user interface is 1, however, user Tom has the right to access commands of level 3; if Tom logs in from VTY 0 user interface, he can access commands of level 3 and lower.

Setting Command Priority The command-privilege level command sets the priority of a specified command in a certain view. The command levels include visit, monitoring, configuration, and management, which are identified with command level 0 through 3, respectively. An administrator assigns authority according to user requirements. See

Ta bl e 13.

Perform the following configuration in system view.

Ta bl e 13 Set Command Priority

Operation Command

Set the command priority in a specified view. command-privilege level level view view

command

Restore the default command level in a specified view.

undo command-privilege view view command

Configuring the Attributes of a Modem

You can use the commands described in Tab le 14 to configure the attributes of a modem when logging in to the Switch through the modem.

Perform the following configuration in user interface view.

Ta bl e 14 Configure Modem

Operation Command

Set the interval since the system receives the RING until CD_UP

Restore the default interval since the system receives the RING until CD_UP

Configure auto answer modem auto-answer

Configure manual answer undo modem auto-answer

Configure to allow call-in modem call-in

Configure to bar call-in undo modem call-in

Configure to permit call-in and call-out. modem both

Configure to disable call-in and call-out undo modem both

modem timer answer seconds

undo modem timer answer

Configuring Redirection

The send Command can be used for sending messages between user interfaces. See

Ta bl e 15.

18 CHAPTER 1: SYSTEM ACCESS

Perform the following configuration in user view.

Ta bl e 15 Configure to Send Messages Between User Interfaces

Operation Command

Configure to send messages between different user interfaces.

send { all | number | type number }

The auto-execute Command is used to run a command automatically after you log in. The command is automatically executed when you log in again. See Ta bl e 16.

This command is usually used to execute the telnet command automatically on a terminal, which connects the user to a designated device.

Perform the following configuration in user interface view.

Ta bl e 16 Configure Automatic Command Execution

Operation Command

Configure to automatically run the command auto-execute command text

Configure not to automatically run the command

undo auto-execute command

After applying the auto-execute command, the user interface can no longer be used to carry out the routine configurations for the local system.

Make sure that you will be able to log in to the system in some other way and cancel the configuration before you use the auto-execute command and save the configuration.

Telnet 10.110.100.1 after the user logs in through VTY0 automatically.:

[SW8800-ui-vty0]auto-execute command telnet 10.110.100.1

When a user logs on by VTY 0, the system will run telnet 10.110.100.1 automatically.

Displaying and Debugging User Interface

After creating the previous configuration, execute the display command in all views to display the user interface configuration, and to verify the effect of the configuration. Execute the free command in user view to clear a specified user interface.

Ta bl e 17 Display and Debug User Interface

Operation Command

Clear a specified user interface free user-interface [ type ] number

Display the user application information of the user interface

Display the physical attributes and some configurations of the user interface

display users [ all ]

display user-interface [ type number ] [

number ] [summary]

See Ta bl e 17.

Command Line Interface 19

Command Line Interface

The Switch 8800 provides a series of configuration commands and command line interfaces for configuring and managing the Switch 8800. The command line interface has the following features.

■ Local configuration through the console and AUX ports.

■ Local or remote configuration through Telnet.

■ Remote configuration through a dial-up Modem through the AUX port to log

in to the Switch 8800.

■ Hierarchy command protection to prevent unauthorized users from accessing

the switch.

■ Access to online Help by entering ?.

■ Network test commands, such as Tracert and Ping, for rapid troubleshooting of

the network.

■ Detailed debugging information to help with network troubleshooting.

■ Ability to log in and manage other Switch 8800s directly, using the telnet

command.

■ FTP service for the users to upload and download files.

■ Ability to view previously executed commands.

■ The command line interpreter that searches for a target not fully matching the

keywords. You can enter the whole keyword or part of it, as long as it is unique and not ambiguous.

Configuring a Command Line Interface is described in the following sections:

■ Command Line View

■ Features and Functions of the Command Line

Command Line View The Switch 8800 provides hierarchy protection for the command lines to prevent

unauthorized users from accessing the switch illegally.

There are four levels of commands:

■ Visit level — involves commands for network diagnosis tools (such as ping and

tracert), command of the switch between different language environments of

user interface (language-mode) and the telnet command. Saving the configuration file is not allowed on this level of commands.

■ Monitoring level — includes the display command and the debugging

command for system maintenance, service fault diagnosis, and so on. Saving the configuration file is not allowed on this level of commands.

■ Configuration level — provides service configuration commands, such as the

routing command and commands on each network layer that are used to provide direct network service to the user.

■ Management level — influences the basic operation of the system and the

system support module which plays a support role for service. Commands at this level involve file system commands, FTP commands, TFTP commands, XModem downloading commands, user management commands, and level setting commands.

20 CHAPTER 1: SYSTEM ACCESS

Login users are also classified into four levels that correspond to the four command levels. After users of different levels log in, they can only use commands at their own, or lower, levels.

To prevent unauthorized users from illegal intrusion, users are identified when switching from a lower level to a higher level with the super [ level ] command. User ID authentication is performed when users at a lower level switch to users at a higher level. Only when correct password is entered three times, can the user switch to the higher level. Otherwise, the original user level remains unchanged.

Command views are implemented according to requirements that are related to one another. For example, after logging in to the Switch 8800, you enter user view, in which you can only use some basic functions, such as displaying the operating state and statistics information. In user view, key in system-view to enter system view, in which you can key in different configuration commands and enter the corresponding views.

The command line provides the following views:

■ User view

■ System view

■ Ethernet Port view

■ VLAN view

■ VLAN interface view

■ Local-user view

■ User interface view

■ FTP client view

■ PIM view

■ RIP view

■ OSPF view

■ OSPF area view

■ Route policy view

■ Basic ACL view

■ Advanced ACL view

■ Layer-2 ACL view

■ RADIUS server group view

■ ISP domain view

■ BGP view

■ ISIS view

The relation diagram of the views is shown in Figure 13.

Figure 13 Relation Diagram of the Views

Ethernet port view

User interface view

VLAN view

VLAN interface view

User view

System view

RIP view

OSPF view

Route policy view

OSPF area view

Basic ACL view

Advanced ACL view

Interface-based ACL view

Layer-2 ACL view

FTP client view

Local-user view

PIM view

RADIUS server group view

Command Line Interface 21

ACL

IS-IS view

Ta bl e 18 describes the function features of different views.

For all views, use the quit command to return to system view and use the return command to return to user view.

Ta bl e 18 Function Feature of Command View

Command view Function Prompt Command to enter

User view Show basic infor-

System view Configure system

Ethernet Port view Configure Ethernet

VLAN view Configure VLAN

VLAN interface view Configure IP interface

mation about operation and statistics

parameters

port parameters

parameters

parameters for a VLAN or a VLAN aggregation

BGP view

<SW8800> Enter right after

connecting the switch

[SW8800] Key in system-view

in user view

[SW8800-Gigabit Ethernet1/1/1]

[SW8800Vlan1]

[SW8800-Vlan-in terface1]

100M Ethernet port view

Gigabit Ethernet port view

Enter vlan 1 in System view

Enter interface vlan-interface 1

System view

22 CHAPTER 1: SYSTEM ACCESS

Table 18 Function Feature of Command View (continued)

Command view Function Prompt Command to enter

Local-user view Configure local user

parameters

User interface view Configure user

interface parameters

FTP Client view Configure FTP Client

[SW8800-useruser1]

Enter local-user user1 in System view

[SW8800-ui0] Enter user-interface

0 in System view

[ftp] Enter ftp in user view

parameters

PIM view Configure PIM

parameters

RIP view Configure RIP

parameters

OSPF view Configure OSPF

parameters

OSPF area view Configure OSPF area

parameters

Route policy view Configure route policy

parameters

[SW8800-PIM] Enter pim in System

view

[SW8800-rip] Enter rip in System

view

[SW8800-ospf] Enter ospf in System

view

[SW8800-ospf-0.

0.0.1]

[SW8800-routepolicy]

Enter area 1 in OSPF view

Enter route-policy policy1 permit node 10 in System view

Basic ACL view Define the rule of

basic ACL

Advanced ACL view Define the rule of

advanced ACL

Layer-2 ACL view Define the rule of

layer-2 ACL

RADIUS server group view

Configure radius parameters

ISP domain view Configure ISP domain

parameters

[SW8800-aclbasic-2000]

[SW8800-acl-adv

-3000]

[SW8800-acllink-4000]

Enter acl number 2000 in System view

Enter acl number 3000 in System view

Enter acl number 4000 in System view

[SW8800-radius-1]Enter radius scheme

1 in System view

[SW8800-isp-163 .net]

Enter domain isp-163.net in System view

Features and Functions

of the Command Line

Tasks for configuring the features and functions of the command line are described as follows:

■ Online Help

■ Common Command Line Error Messages

■ History Command

■ Editing Features of the Command Line

■ Displaying Features of the Command Line

Online Help

The command line interface provides full and partial online Help modes.

You can get the help information through these online help commands, which are described as follows.

■ Enter ? in any view to get all the commands in it and corresponding

descriptions.

<SW8800>? User view commands: language-mode Specify the language environment ping Ping function

Command Line Interface 23

quit Exit from current command view super Enter the command workspace with specified user priority level telnetEstablish one TELNET connection tracertTrace route function

■ Enter a command with a ?, separated by a space. If this position is for

keywords, then all the keywords and the corresponding brief descriptions will be listed.

<SW8800>ping ?

-a Select source IP address

-c Specify the number of echo requests to send

-d Specify the SO_DEBUG option on the socket being used

-h Specify TTL value for echo requests to be sent

-I Select the interface sending packets

-n Numeric output only. No attempt will be made to lookup host addresses for symbolic names

-p No more than 8 "pad" hexadecimal characters to fill out the sent packet. For example, -p f2 will fill the sent packet with f and 2 repeatedly

-q Quiet output. Nothing is displayed except the summary lines at startup time and when finished

-r Record route. Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays the route

-s Specifies the number of data bytes to be sent

-t Timeout in milliseconds to wait for each reply

-v Verbose output. ICMP packets other than ECHO_RESPONSE that are received are listed STRING<1-20> IP address or hostname of a remote system Ip IP Protocol

■ Enter a command with a ?, separated by a space. If this position is for

parameters, all the parameters and their brief descriptions will be listed.

[SW8800]garp timer leaveall ? INTEGER<65-32765> Value of timer in centiseconds (LeaveAllTime > (LeaveTime [On all ports])) Time must be multiple of 5 centiseconds [SW8800]garp timer leaveall 300 ? <cr>

<cr> indicates no parameter in this position. The next command line repeats the command, you can press Enter to execute it directly.

■ Enter a character string with a ?, and list all the commands beginning with this

character string.

<SW8800>p? ping

■ Input a command with a character string and ?, and list all the key words

beginning with this character string in the command.

<SW8800>display ver? version

24 CHAPTER 1: SYSTEM ACCESS

Common Command Line Error Messages

All the commands that are entered by users can be correctly executed if they have passed the grammar check. Otherwise, error messages are reported to users. Common error messages are listed in

Ta bl e 19 Common Command Line Error Messages

Error messages Causes

Unrecognized command Cannot find the command.

Cannot find the keyword. Wrong parameter type.

The value of the parameter exceeds the range. Incomplete command

The command is incomplete. Too many parameters

You entered too many parameters. Ambiguous command

The parameters you entered are not specific.

Ta bl e 19.

History Command

The command line interface provides a function similar to DosKey. The commands entered by users can be automatically saved by the command line interface and you can invoke and execute them at any time. By default, the history command buffer can store 10 history commands for each user. The operations are shown in Ta bl e 20.

Ta bl e 20 Retrieve History Command

Operation Key Result

Display history command display history-command Displays history commands

Retrieve the previous history command

Retrieve the next history command

Up cursor key <> or <Ctrl+P> Retrieves the previous history

Down cursor key <> or <Ctrl+N>

by the user who is entering them.

command, if there is any.

Retrieves the next history command, if there is any.

Editing Features of the Command Line

The command line interface provides a basic command editing function and supports editing multiple lines. A command cannot be longer than 256 characters.

Ta bl e 21.

See

Ta bl e 21 Editing Functions

Key Function

Common keys Inserts at the cursor position and the cursor

moves to the right, if the edition buffer still has free space.

Backspace Deletes the character preceding the cursor

and the cursor moves backward.

Left cursor key < or Ctrl+B Moves the cursor a character backward

Right cursor key > or Ctrl+F Moves the cursor a character forward

Up cursor key ^ or Ctrl+P Down cursor key v or Ctrl+N

Retrieves the history command.

Command Line Interface 25

Table 21 Editing Functions

Key Function

Tab Press Tab after typing the incomplete key

word and the system will execute the partial help: If the key word matching the typed one is unique, the system will replace the typed one with the complete key word and display it in a new line. If there is not a matched key word or the matched key word is not unique, the system will do no modification but displays the originally typed word in a new line.

Displaying Features of the Command Line

If information to be displayed exceeds one screen, the pause function allows users three choices, as described in

Ta bl e 22 Display Functions

Key or Command Function

Press Ctrl+C when the display pauses Stop displaying and executing command.

Enter a space when the display pauses Continue to display the next screen of

Press Enter when the display pauses Continue to display the next line of

Tab le 22.

information.

26 CHAPTER 1: SYSTEM ACCESS

PORT CONFIGURATION

This chapter covers the following topics:

■ Ethernet Port Overview

■ Configuring Link Aggregation

Ethernet Port Overview

Configuring Ethernet

Ports

The following features are found in the Ethernet ports of the Switch 8800:

■ 10GBASE-X-XENPAK 10-Gigabit Ethernet ports work in 10-gigabit full duplex

mode.

■ 10GBASE-X-XFP operates in 10 Gbps full duplex mode, which needs no

configuring.

■ 1000BASE-X-SFP Gigabit Ethernet ports work in gigabit full duplex mode.

■ 10/100/1000BASE-T Gigabit Ethernet ports support MDI/MDI-X auto-sensing,

and the modes are 1000 Mbps full duplex, 100 Mbps half/full duplex, and 10 Mbps half/full duplex. These modules also support auto-negotiation

Configuring an Ethernet port is described in the following sections:

■ Configuring Ethernet Ports

■ Example: Configuring the Default VLAN ID of the Trunk Port

■ Troubleshooting VLAN Port Configuration

Tasks for configuring Ethernet ports are described in the following sections:

■ Entering Ethernet Port View

■ Enabling and Disabling Ethernet Ports

■ Setting the Description Character String for an Ethernet Port

■ Setting the Duplex Attribute of the Ethernet Port

■ Setting the Speed of the Ethernet Port

■ Setting the Cable Type for an Ethernet Port

■ Setting Flow Control for an Ethernet Port

■ Permitting/Forbidding Jumbo Frames on the Ethernet port

■ Setting the Maximum MAC Addresses an Ethernet Port Can Learn

■ Setting the Link Type for an Ethernet Port

■ Adding an Ethernet Port to a VLAN

■ Setting the Default VLAN ID for an Ethernet Port

■ Copying a Port Configuration to Other Ports

28 CHAPTER 2: PORT CONFIGURATION

■ Displaying and Debugging Ethernet Ports

Entering Ethernet Port View

Before configuring the Ethernet port, enter Ethernet port view.

Perform the following configuration in system view.

Ta bl e 1 Enter Ethernet Port View

Operation Command

Enter Ethernet port view interface { Gigabit | Ethernet }

The subslot on the Fabric is always set to 1.

Enabling and Disabling Ethernet Ports

The following command can be used for disabling or enabling the port. After configuring the related parameters and protocol of the port, you can use the following command to enable the port.

Perform the following configuration in Ethernet port view.

slot/subslot/port

Ta bl e 2 Enable/Disable an Ethernet Port

Operation Command

Disable an Ethernet port shutdown

Enable an Ethernet port undo shutdown

By default, the port is enabled.

Setting the Description Character String for an Ethernet Port

You can use the following command to identify the Ethernet ports.

Perform the following configuration in Ethernet port view.

Ta bl e 3 Set Description Character String for Ethernet Port

Operation Command

Set description character string for Ethernet port.

Delete the description character string of Ethernet.

description text

undo description

By default, the port description is a null character string.

Setting the Duplex Attribute of the Ethernet Port

Set the port to full duplex to send and receive data packets at the same time. Set the port to half-duplex to either send or receive only. If the port has been set to auto-negotiation mode, the local and peer ports will automatically negotiate the duplex mode.

Ethernet Port Overview 29

Perform the following configuration in Ethernet port view.

Ta bl e 4 Set the Duplex Attribute for an Ethernet Port

Operation Command

Set the duplex attribute for an Ethernet port. duplex {auto | full | half}

Restore the default duplex attribute of Ethernet port.

undo duplex

The Gigabit Ethernet Base-T ports can operate in full duplex, half duplex, or auto-negotiation mode. When the ports operate at 1000 Mbps, the duplex mode can be set to full (full duplex) or auto (auto-negotiation).

By default, the port is in auto (auto-negotiation) mode.

Setting the Speed of the Ethernet Port

You can use the following command to set the speed on the Ethernet port. If the speed is set to auto (auto-negotiation) mode, the local and peer ports will automatically negotiate the port speed.

Perform the following configuration in Ethernet port view.

Ta bl e 5 Set Speed on Ethernet Port

Operation Command

Set Ethernet port speed speed {10 | 100 | 1000 | auto}

Restore the default speed on Ethernet port undo speed

The Gigabit Ethernet BASE-T port can operate at 10 Mbps, 100 Mbps, or 1000 Mbps. However in half duplex mode, the port cannot operate at 1000 Mbps. The Gigabit optical Ethernet port supports1000 Mbps; the 10 Gigabit optical Ethernet port supports 10000 Mbps, which does not need to be configured.

Setting the Cable Type for an Ethernet Port

The Ethernet port supports the straight-through (MDI) and cross-over (MDIX) network cables. The Switch 8800 only supports auto (auto-sensing). If you set some other type, you will see an error message. By default, the cable type is auto (auto-recognized). The system will automatically recognize the type of cable connecting to the port.

Perform the following configuration in Ethernet port view. The settings only take effect on 10/100/1000 Mbps electrical ports.

Ta bl e 6 Set the Type of the Cable Connected to the Ethernet Port

Operation Command

Set the type of the cable connected to the Ethernet port.

Restore the default type of the cable connected to the Ethernet port.

mdi { auto }

undo mdi

Setting Flow Control for an Ethernet Port

If flow control is enabled on both the local and the peer switch and congestion occurs in the local switch, the local switch can instruct its peer to temporarily stop sending packets. Once the peer switch receives this message, it stops sending

30 CHAPTER 2: PORT CONFIGURATION

packets and packet loss is reduced. The flow control function of the Ethernet port can be enabled or disabled using the following commands.

Perform the following configuration in Ethernet port view.

Ta bl e 7 Set Flow Control for Ethernet Port

Operation Command

Enable Ethernet port flow control flow-control

Disable Ethernet port flow control undo flow-control

By default, Ethernet port flow control is disabled.

Permitting/Forbidding Jumbo Frames on the Ethernet port

Using the jumbo frame enable command, you can allow jumbo frames (1523 to to 9216 bytes) to pass through the specified Ethernet port. Note that packets of 1518 to 1522 bytes, including the IEEE 802.1Q tagging are always allowed to pass through Ethernet ports.

Jumbo frames are only allowed for Ethernet Type II frames. Most network equipment, including NICs, switches, and routers are not capable of supporting jumbo frames and will always discard these packets.

Perform the following configuration in Ethernet port view.

Ta bl e 8 Permitting/Forbidding Jumbo Frames to Pass Through the Ethernet Port

Operation Command

Permit jumbo frame to pass through the Ethernet port.

Forbid jumbo frame to pass through the Ethernet port.

jumboframe enable [ jumboframe_value ]

undo jumboframe enable

By default, jumbo frames are disabled.

Setting the Maximum MAC Addresses an Ethernet Port Can Learn

Use the following command to set a limit on the number of MAC addresses that an Ethernet port will learn.

Perform the following configuration in Ethernet port view.

Ta bl e 9 Set a Limit on the Number of MAC Addresses Learned by an Ethernet Port

Operation Command

Set a limit on the number of MAC addresses learned by an Ethernet port

Restore the default limit on MAC addresses learned by the Ethernet port

mac-address max-mac-count count

undo mac-address max-mac-count

If the count parameter is set to 0, the port is not permitted to learn MAC address. By default, there is no limit to the amount of the MAC addresses that an Ethernet port can learn. However the number of MAC addresses a port can learn is still restricted by the size of the MAC address table.

Ethernet Port Overview 31

Setting the Ethernet Port Broadcast Suppression Ratio

You can use the following commands to restrict the broadcast traffic. Once the broadcast traffic exceeds the value set by the user, the system maintains an appropriate broadcast packet ratio by discarding the overflow traffic. This is done to suppress broadcast storm, avoid congestion, and ensure good traffic flow.

The parameter indicates the maximum wire speed ratio of the broadcast traffic allowed on the port. The smaller the ratio, the smaller the amount of broadcast traffic allowed. If the ratio is 100%, broadcast storm suppression is not performed on the port.

Perform the following configuration in Ethernet port view.

Ta bl e 10 Setting the Ethernet Port Broadcast Suppression Ratio

Operation Command

Set the Ethernet port broadcast suppression ratio

Restore the default Ethernet port broadcast suppression ratio

broadcast-suppression pct

undo broadcast-suppression

By default, 100% broadcast traffic is allowed to pass through and no broadcast suppression is performed.

Setting the Link Type for an Ethernet Port

An Ethernet port can operate in three different link modes, access, hybrid, and trunk. The management access port carries one VLAN only and is used for connecting to the user’s computer.

A trunk port can belong to more than one VLAN and can transmit packets on multiple VLANs. A hybrid port can also belong to more than one VLAN and transmit packets on multiple VLANs.

However, the hybrid port allows packets from multiple VLANs to be sent without tags but the trunk port only allows packets from the default VLAN to be sent without tags.

Perform the following configuration in Ethernet port view.

Ta bl e 11 Set the Link Type for an Ethernet Port

Operation Command

Configure the port as an access port port link-type access

Configure the port as a hybrid port port link-type hybrid

Configure the port as a trunk port port link-type trunk

Restore the default link type, that is, the access port.

undo port link-type

A port on a switch can be configured as an access port, a hybrid port, or a trunk port. However, to reconfigure between hybrid and trunk link types, you must first restore the default, or access link type.

The default port link type is the access link type.

32 CHAPTER 2: PORT CONFIGURATION

Adding an Ethernet Port to a VLAN

The following commands are used for adding an Ethernet port to a specified VLAN. Access ports can be added to only one VLAN, while hybrid and trunk ports can be added to multiple VLANs.

Perform the following configuration in Ethernet port view.

Ta bl e 12 Adding an Ethernet Port to Specified VLANs

Operation Command

Add the current access port to a specified VLAN

Add the current hybrid port to specified VLANs

Add the current trunk port to specified VLANs port trunk permit vlan {vlan_id_list | all}

Remove the current access port from to a specified VLAN.

Remove the current hybrid port from to specified VLANs.

Remove the current trunk port from specified VLANs.

port access vlan vlan_id

port hybrid vlan vlan_id_list {tagged | untagged}

undo port access vlan

undo port hybrid vlan vlan_id_list

undo port trunk permit vlan {vlan_id_list | all}

The access port will be added to an existing VLAN other than VLAN 1. The VLAN to which a Hybrid port is added must exist. The VLAN to which a Trunk port is added cannot be VLAN 1.

After adding the Ethernet port to the specified VLANs, the local port can forward packets from these VLANs. The hybrid and trunk ports can be added to multiple VLANs, thereby, implementing the VLAN intercommunication between peers. For the hybrid port, you can tag VLAN packets to process packets in different ways, depending on the target device.

Setting the Default VLAN ID for an Ethernet Port

An access port can only be included in one VLAN so its default VLAN is the VLAN to which it belongs.

The hybrid port and the trunk port can be included in several VLANs but a default VLAN ID must be configured. If the default VLAN ID has been configured, the packets without a VLAN tag are forwarded to the port that belongs to the default VLAN. When the system sends packets with a VLAN tag, if the VLAN ID of the packet is identical to the default VLAN ID of the port, the system will remove the VLAN tag before sending this packet.

Perform the following configuration in Ethernet port view.

Ta bl e 13 Set the Default VLAN ID for the Ethernet Port

Operation Command

Set the default VLAN ID for the hybrid port. port hybrid pvid vlan vlan_id

Set the default VLAN ID for the trunk port port trunk pvid vlan vlan_id

Restore the default VLAN ID of the hybrid port to the default value

Restore the default VLAN ID of the trunk port to the default value

undo port hybrid pvid

undo port trunk pvid

Ethernet Port Overview 33

To guarantee proper packet transmission, the default VLAN ID of local hybrid port or Trunk port should be identical to that of the hybrid port or Trunk port on the peer switch. The VLAN of hybrid port and trunk port is VLAN 1 by default. The access port is the VLAN to which it belongs.

Copying a Port Configuration to Other Ports

To keep the configuration of other ports consistent with a specified port, you can copy the configuration of that specified port to other ports. Port configuration involves the following settings:

■ STP setting — includes STP enabling/disabling, link attribute (point-to-point or

not), STP priority, path cost, max transmission speed, loop protection, root protection, edge port or not.

■ QoS setting — includes traffic limiting, priority marking, default 802.1p priority,

bandwidth assurance, congestion avoidance, traffic redirection, traffic statistics.

■ VLAN setting — includes permitted VLAN types, default VLAN ID.

■ Port setting — includes port link type, port speed, duplex mode.

Perform the following configuration in system view.

Ta bl e 14 Copying a Port Configuration to Other Ports

Operation Command

Copy port configuration to other ports copy configuration source { interface-type

interface-number | interface-name | aggregation-group agg-id } destination { interface_list [ aggregation-group agg-id ] |

aggregation-group agg-id }

Note that if the copy source is an aggregation group, use the port with the lowest ID as the source. If the copy destination is an aggregation group, make the configurations of all group member ports identical with that of the source.

Displaying and Debugging Ethernet Ports

After configuration, execute the display command in all views to display the current configuration of Ethernet port parameters, and to verify the configuration.

Use the reset command in user view to clear the statistics from the port.

Use the loopback command in Ethernet port view to configure the Ethernet port in internal loop mode. Use the undo loopback command in Ethernet port view to cancel the loop setting.

Ta bl e 15 Display and Debug Ethernet Port

Operation Command

Display all the information of the port display interface {interface_type |

Display hybrid port or trunk port display port {hybrid | trunk}

Clear the statistics information of the port reset counters interface [interface_type |

interface_type interface_num | interface_name}

interface_type interface_num | interface_name]

34 CHAPTER 2: PORT CONFIGURATION

Example: Configuring

the Default VLAN ID of

the Trunk Port

In this example, Switch A is connected to the peer, Switch B, through the trunk port GigabitEthernet2/1/1. Configure the trunk port with a default VLAN ID, so that the port can forward packets to the member ports belonging to the default VLAN when it receives them without a VLAN tag. When it sends the packets with VLAN tag and the packet VLAN ID is the default VLAN ID, the trunk port removes the packet VLAN tag and forward the packet.

Figure 1 Configure the Default VLAN for a Trunk Port

Switch A

Switch B

The following configurations are used for Switch A, configure Switch B in a similar way:

1 Enter the Ethernet port view of Ethernet2/1/1.

[SW8800]interface gigabitethernet2/1/1

2 Set the GigabitEthernet2/1/1 to be a trunk port which allows VLAN 2, 6 through

50, and 100 to pass through.

[SW8800-GigabitEthernet2/1/1]port link-type trunk [SW8800-GigabitEthernet2/1/1]port trunk permit vlan 2 6 to 50 100

Troubleshooting VLAN

Port Configuration

Configuring Link Aggregation

3 Create the VLAN 100.

[SW8800]vlan 100

4 Configure the default VLAN ID of GigabitEthernet2/1/1 as 100.

[SW8800-GigabitEthernet2/1/1]port trunk pvid vlan 100

If the default VLAN ID configuration fails, take the following steps:

1 Execute the display interface or display port command to check if the port is a

trunk port or a hybrid port. If it is neither, configure it as a trunk port or a hybrid port.

2 Then configure the default VLAN ID.

Link aggregation means aggregating several ports together to implement the outgoing/incoming payload balance among the member ports and to enhance connection reliability.

For the member ports in an aggregation group, their basic configurations must be the same. That is, if one is a trunk port, others must be trunk ports also. If a port turns into an access port, then others must change to access ports.

Basic configuration includes:

■ STP setting

■ STP enabling and disabling

■ Link attribute (point-to-point or not)

■ STP priority

■ Path cost

■ Maximum transmission speed

■ Loop protection

■ Root protection

■ Type of port (edge)

■ QoS setting

■ Traffic limiting

■ Priority marking

■ Default 802.1p priority

■ Bandwidth assurance

■ Congestion avoidance

■ Traffic redirection

■ Traffic statistics.

■ VLAN setting

Configuring Link Aggregation 35

■ Permitted VLAN types

■ Default VLAN ID

■ Port setting

■ Port link type

The Switch 8800 supports a maximum of 31 link aggregation groups, with a maximum of eight ports in each group.

Load Sharing Link aggregation may be load balancing aggregation or non-load balancing

aggregation. In general, the system only provides limited load balancing aggregation resources, so the system needs to rationally allocate these resources among aggregation groups. The system will always allocate hardware aggregation resources to the aggregation groups with higher priority levels. When the load sharing aggregation resources are used up for existing aggregation groups, newly-created aggregation groups will be non-load sharing groups. The priority levels (in descending order) for allocating load sharing aggregation resources are aggregation groups that:

■ Include special ports which require hardware aggregation resources

■ Are likely to reach the maximum rate after the resources are allocated to them

■ Have the minimum master port numbers if they reach an equal rate with other

groups after the resources are allocated to them

When aggregation groups of higher priority levels appear, the aggregation groups of lower priority levels release their hardware resources. For single-port aggregation groups, if they can transmit packets normally without occupying hardware resources, they cannot occupy the resources.

36 CHAPTER 2: PORT CONFIGURATION

Port State In an aggregation group, ports may be in selected or standby state and only the

selected ports can transmit user service packets. The selected port with the minimum port number serves as the master port, while others serve as sub-ports.

In an aggregation group, the system sets the ports to selected or standby state based on these rules:

■ The system sets the port with the highest priority to selected state, and sets

■ The system sets to standby state the ports which cannot aggregate with the

■ The system sets to standby state the ports with basic configurations different

others to standby state based on the descending order of priority levels, as follows:

■ full duplex/high speed

■ full duplex/low-speed

■ half duplex/high speed

■ half duplex/low speed

selected port with the lowest port number, due to hardware limits.

from that of the selected port with the lowest port number.

Configuring Link

Aggregation

Only a defined number of ports can be supported in an aggregation group, so if the selected ports in an aggregation group exceed the port quantity threshold for that group, the system sets some ports with smaller port numbers (in ascending order) as selected ports and others as standby ports. The selected ports can transmit user service packets, but standby ports cannot.

A load sharing aggregation group may contain several selected ports, but a non-load sharing aggregation group can only have one selected port, while others are standby ports.

The Switch 8800 only supports link aggregation for ports on the same I/O module. A maximum number of 8 ports can be selected in a link aggregation. For modules that have fewer than 8 ports, such as the 2-port 10GBASE-X module, only two ports can be selected members of a link aggregation.

Link aggregation configuration includes tasks described in the following sections:

■ Creating or Deleting an Aggregation Group

■ Adding or Deleting Ethernet Ports to or from an Aggregation Group

■ Setting or Deleting an Aggregation Group Descriptor

■ Displaying and Debugging Link Aggregation

Creating or Deleting an Aggregation Group

You can use the following command to create a manual aggregation group. You can also delete an existing aggregation group. When you delete a manual aggregation group, all its member ports are removed from the aggregation.

Configuring Link Aggregation 37

Perform the following configuration in system view.

Ta bl e 16 Create or Delete an Aggregation Group

Operation Command

Create an aggregation group link-aggregation group agg-id mode {

manual }

Delete an aggregation group undo link-aggregation group agg-id

Adding or Deleting Ethernet Ports to or from an Aggregation Group

You can use the following commnad to add or delete ports into/from a manual aggregation group.

Perform the following configuration in corresponding view.

Ta bl e 17 Adding or Deleting an Ethernet Port to or from an Aggregation Group

Operation Command

Add an Ethernet port into the aggregation group (Ethernet port view)

Delete an Ethernet port from the aggregation port (Ethernet port view)

Aggregate Ethernet ports (System view) link-aggregation interface_name1 to

port link-aggregation group agg-id

undo port link-aggregation group

interface_name2 [ both ]

Note that you must delete the aggregation group, instead of the port, if the manual aggregation group contains only one port.

Setting or Deleting an Aggregation Group Descriptor

Perform the following configuration in system view.

Ta bl e 18 Setting or Deleting an Aggregation Group Descriptor

Operation Command

Set aggregation group descriptor link-aggregation group agg-id description

Delete aggregation group descriptor undo link-aggregation group agg-id

alname

description

By default, an aggregation group has no descriptor.

Displaying and Debugging Link Aggregation

After you have completed your configuration, execute the display command in any view to display the link aggregation configuration, and to verify the effect of the configuration.

Ta bl e 19 Display and Debug Link Aggregation

Operation Command

Display summary information of all aggregation groups

Display detailed information of a specific aggregation group

display link-aggregation summary

display link-aggregation verbose agg-id

38 CHAPTER 2: PORT CONFIGURATION

Table 19 Display and Debug Link Aggregation (continued)

Operation Command

Display detailed link aggregation information at the port

Disable/enable debugging link aggregation errors

Disable/enable debugging link aggregation events

display link-aggregation interface {

interface-type interface-number | interface-name } [ to { interface-type interface-num | interface-name } ]

[ undo ] debugging link-aggregation error

[ undo ] debugging link-aggregation

event

Example: Link

Aggregation

Configuration

Switch A connects switch B with three aggregation ports, numbered as GigabitEthernet2/1/1 to GigabitEthernet2/1/3, so that the incoming and outgoing loads can be balanced among the member ports.

Figure 2 Networking For Link Aggregation

Link aggregation

Switch A Switch B

The following code example lists only the configuration for switch A. The configuration for switch B is similar.

1 Configure aggregation group 1.

[SW8800]link-aggregation group 1 mode manual

Add Ethernet ports GigabitEthernet2/1/1 to GigabitEthernet2/1/3 into aggregation group 1.

[SW8800]interface gigabitethernet2/1/1 [SW8800-GigabitEthernet2/1/1]port link-aggregation group 1 [SW8800-GigabitEthernet2/1/1]interface ethernet2/1/2 [SW8800-GigabitEthernet2/1/2]port link-aggregation group 1 [SW8800-GigabitEthernet2/1/2]interface ethernet2/1/3 [SW8800-GigabitEthernet2/1/3]port link-aggregation group 1

VLAN CONFIGURATION

This chapter covers the following topics:

■ VLAN Overview

■ Configuring VLANs

■ Configuring GARP/GVRP

VLAN Overview A virtual local area network (VLAN) creates logical groups of LAN devices into

segments to implement virtual workgroups.

Using VLAN technology, you can logically divide the physical LAN into different broadcast domains. Every VLAN contains a group of workstations with the same resource requirements. However, the workstations of a VLAN do not have to belong to the same physical LAN segment.

Within a VLAN, broadcast and unicast traffic is not forwarded to other VLANs. Therefore, VLAN configurations are very helpful in controlling network traffic, simplifying network management, and improving security.

The Switch 8800 supports port-based VLANs, which define VLAN members according to switch ports. This is the simplest and most efficient way to create VLANs.

Configuring VLANs The following sections describe how to configure VLANs:

■ Common VLAN Configuration Tasks

Common VLAN

Configuration Tasks

The following sections discuss the common tasks for configuring a VLAN:

■ Creating or Deleting a VLAN

■ Adding Ethernet Ports to a VLAN

■ Setting or Deleting the VLAN Description Character String

■ Specifying or Removing VLAN Interfaces

■ Shutting Down or Enabling a VLAN Interface

■ Displaying and Debugging a VLAN

Creating or Deleting a VLAN

Use the following command to create or delete a VLAN.

40 CHAPTER 3: VLAN CONFIGURATION

Perform the following configurations in system view.

Ta bl e 1 Creating or Deleting a VLAN

Operation Command

Create and enter a VLAN view vlan vlan_id

Delete the specified VLAN undo vlan { vlan_id [ to vlan_id ] / all }

The command creates the VLAN then enters the VLAN view. If the VLAN already exists, the command enters the VLAN view directly.

Note that the default VLAN, VLAN 1, cannot be deleted.

Adding Ethernet Ports to

a VLAN

Use the port interface_list command to add the Ethernet ports to a VLAN.

Perform the following configuration in VLAN view.

Ta bl e 2 Adding Ethernet Ports to a VLAN

Operation Command

Add Ethernet ports to a VLAN port interface_list

Remove Ethernet ports from a VLAN undo port interface_list

By default, the system adds all the ports to a default VLAN, whose ID is 1.

You can add or delete trunk port and hybrid ports to or from a VLAN by the port and undo port commands in Ethernet port view, but not in VLAN view.

Setting or Deleting the VLAN Description Character String

You can use the following command to set or delete the VLAN description character string.

You can use description character strings, such as workgroup_name and department_name, to distinguish the different VLANs.

Perform the following configuration in VLAN view.

Ta bl e 3 Setting and Deleting VLAN Description Character String

Operation Command

Set the description character string for the specified VLAN

Delete the description character string of the specified VLAN

description string

undo description

By default, the VLAN description character string is the VLAN ID of the VLAN, VLAN 0001. The VLAN interface description character string is the VLAN interface name, for example, 3Com, Switch 8800, Vlan-interface1 Interface.

Specifying or Removing VLAN Interfaces

You can use the following command to specify or remove the VLAN interfaces. To implement the network layer function on a VLAN interface, the VLAN interface should be configured with an IP address and mask. For the corresponding configuration, refer to

“Network Protocol Operation” on page 49.

Configuring VLANs 41

Perform the following configurations in system view.

Ta bl e 4 Specifying and Removing VLAN interfaces

Operation Command

Create a new VLAN interface and enter VLAN interface view

Remove the specified VLAN interface

interface vlan-interface vlan_id

undo interface vlan-interface vlan_id

Create a VLAN before creating an interface for it.

Shutting Down or Enabling a VLAN Interface

Use the following command to shut down or enable a VLAN interface.

Perform the following configuration in VLAN interface view.

Ta bl e 5 Shutting Down or Enabling a VLAN Interface

Operation Command

Shut down the VLAN interface shutdown

Enable the VLAN interface undo shutdown

Example: VLAN

Configuration

The operation of shutting down or enabling the VLAN interface has no effect on the UP/DOWN status of the Ethernet ports in the VLAN.

By default, when the status of all Ethernet ports in a VLAN is DOWN, the status of the VLAN interface is DOWN also so the VLAN interface is shut down. When the status of one or more Ethernet ports is UP, the status of the VLAN interface is UP also, so the VLAN interface is enabled.

Displaying and Debugging a VLAN

After the configuring a VLAN, execute the display command in any view to display the VLAN configuration, and to verify the effect of the configuration.

Ta bl e 6 Displaying and Debugging a VLAN

Operation Command

Display the information about a VLAN interface

Display the information about a VLAN display vlan [ vlan_id | all | static | dynamic ]

display interface vlan-interface [ vlan_id ]

Create VLAN2 and VLAN3. Add GigabitEthernet3/1/1 and GigabitEthernet4/1/1 to VLAN2 and add GigabitEthernet3/1/2 and GigabitEthernet4/1/2 to VLAN3.

42 CHAPTER 3: VLAN CONFIGURATION

Figure 1 VLAN Configuration Example

Switch 8800

Configuring GARP/GVRP

E3/1/1

VLAN2

E4/1/1

E3/1/2

VLAN3

E4/1/2

1 Create VLAN 2 and enter its view.

[SW8800]vlan 2

2 Add GigabitEthernet3/1/1 and GigabitEthernet4/1/1 to VLAN2.

[SW8800-vlan2]port GigabitEthernet3/1/1 GigabitEthernet4/1/1

3 Create VLAN 3 and enters its view.

[SW8800-vlan2]vlan 3

4 Add GigabitEthernet3/1/2 and GigabitEthernet4/1/2 to VLAN3.

[SW8800-vlan3]port GigabitEthernet3/1/2 GigabitEthernet4/1/2

Generic Attribute Registration Protocol (GARP), allows members in the same switching network to distribute, propagate, and register information, such as VLAN and multicast addresses.

GARP does not exist in a switch as an entity. A GARP participant is called a GARP application. The main GARP applications are GVRP and GMRP. GVRP is described

Configuring GARP/GVRP and GMRP is described in “GMRP” on page 203.

in When a GARP participant is on a port of the switch, each port corresponds to a GARP participant.

Through GARP, configuration information on one GARP member is advertised to the entire switching network. A GARP member can be a terminal workstation or a bridge. A GARP member can notify other members to register or remove its

Configuring GARP/GVRP 43

attribute information by sending join declarations or withdrawal declarations. It can also register or remove the attribute information of other GARP members according to the join declarations or withdrawal declarations that it receives from them.

GARP members exchange information by sending GARP messages. There are three main types of GARP messages, including join, leave, and leaveall. When a GARP participant wants to register its attribute information on other switches, it sends a join message. When the GARP participant wants to remove its attribute information from other switches, it sends a leave message. The leaveall timer is started at the same time that each GARP participant is enabled and a leaveall message is sent out when the leaveall timer times out. The join and leave messages cooperate to ensure the logout and the re-registration of a message. By exchanging messages, all the attribute information to be registered can be propagated to all the switches in the same switching network.

The destination MAC addresses of the packets of the GARP participants are specific multicast MAC addresses. A switch that supports GARP classifies the packets that it receives from GARP participants and processes them with the corresponding GARP applications (GVRP or GMRP).

GARP and GMRP are described in detail in the IEEE 802.1p standard. The Switch 8800 fully supports GARP compliant with the IEEE standards.

■ The value of the GARP timer is used in all GARP applications, including GVRP

and GMRP, that are running in a switched network.

■ In one switched network, GARP timers on all the switching devices should be

set to the same value.

Setting the GARP Timers

GARP timers include the hold, join, and leaveall timers.

The GARP participant sends join message regularly when the join timer times out so that other GARP participants can register its attribute values.

When the GARP participant wants to remove attribute values, it sends a leave message. When the leave message arrives, the receiving GARP participant starts the leave timer. If the receiving participant does not receive a join message from the sender before the leave timer expires, the receiving participant removes the sender’s GARP attribute values.

The leaveall timer is started as soon as a GARP participant joins. A leaveall message is sent at timeout so that other GARP participants remove all the attribute values of this participant. Then, the leaveall timer is restarted and a new cycle begins.

When a switch receives GARP registration information, it does not send a join message immediately. Instead, it enables a hold timer and sends the join message outward when the hold timer times out. In this way, all the VLAN registration

44 CHAPTER 3: VLAN CONFIGURATION

information received within the time specified by the hold timer can be sent in one frame to save bandwidth.

Ta bl e 7 Setting the GARP Timers

Operation Command

Configure the hold, join, and leave timers in Ethernet port view.

Set the GARP hold, join, and leave timers

Restore the default GARP hold, join, and leave timer settings

Configure the leaveall timer in system view.

Set GARP leaveall timer garp timer leaveall timer_value

Restore the default GARP leaveall timer settings.

The value of the join timer should be no less than twice the value of the hold timer, and the value of the leave timer should be greater than twice the value of the join timer and smaller than the leaveall timer value. Otherwise, the system displays an error message.

garp timer { hold | join | leave } timer_value

undo garp timer { hold | join | leave }

undo garp timer leaveall

Join timer > 2 x hold timer > leave timer < leavall timer

GARP timers have the following default values:

■ Hold timer — 10 centiseconds

■ Join timer — 20 centiseconds,

■ Leave timer — 60 centiseconds

■ Leaveall timer — 1000 centiseconds.

Displaying and Debugging GARP

After you configure the GARP timer, use the display command in all views to display the GARP configuration, and to verify the effect of the configuration.

Execute the reset command in user view to reset the GARP configuration.

Execute the debugging command in user view to debug the GARP configuration.

Ta bl e 8 Display and Debug GARP

Operation Command

Display GARP statistics information display garp statistics [ interface interface-list ]

Display GARP timer display garp timer [ interface interface-list ]

Reset GARP statistics information reset garp statistics [ interface interface-list ]

Enable GARP event debugging debugging garp event

Disable GARP event debugging undo debugging garp event

Configuring GVRP GARP VLAN Registration Protocol (GVRP) is a GARP application. GVRP is based on

the GARP, and maintains the dynamic VLAN registration information in the switch and distributes the information to other switches. All the GVRP-supporting switches can receive VLAN registration information from other switches and can

Configuring GARP/GVRP 45

dynamically update local VLAN registration information, including the active members and the port through which each member can be reached.

All the switches that support GVRP can distribute their local VLAN registration information to other switches so that VLAN information is consistent on all GVRP devices in the same network. The VLAN registration information that is distributed by GVRP includes both the local static registration information that is configured manually and the dynamic registration information received from other switches.

GVRP is described in the IEEE 802.1Q standard. The Switch 8800 fully supports GARP compliant with the IEEE standards.

GVRP configuration steps include tasks described in the following sections:

■ Enabling or Disabling Global GVRP

■ Enabling or Disabling Port GVRP

■ Setting the GVRP Registration Type

When you configure GVRP, you need to enable it globally and for each port participating in GVRP. Similarly, the GVRP registration type can take effect only after you configure port GVRP. In addition, you must configure GVRP on the trunk port.

Enabling or Disabling Global GVRP

Use the following commands to enable or disable global GVRP.

Perform the following configurations in system view.

Ta bl e 9 Enabling/Disabling Global GVRP

Operation Command

Enable global GVRP gvrp

Disable global GVRP undo gvrp

By default, GVRP is disabled on a port.

Enabling or Disabling Port GVRP

Use the following commands to enable or disable GVRP on a port.

Perform the following configurations in Ethernet port view.

Ta bl e 10 Enabling/Disabling Port GVRP

Operation Command

Enable port GVRP gvrp

Disable port GVRP undo gvrp

You should enable GVRP globally before you enable it on the port. GVRP can only be enabled or disabled on a trunk port.

By default, global GVRP is disabled.

46 CHAPTER 3: VLAN CONFIGURATION

Setting the GVRP Registration Type

The GVRP includes normal, fixed, and forbidden registration types (see IEEE

802.1Q).

■ When an Ethernet port registration type is set to normal, the dynamic and

■ When one trunk port registration type is set to fixed, the system adds the port

■ When an Ethernet port registration type is set to forbidden, all the VLANs

Perform the following configurations in Ethernet port view.

Ta bl e 11 Setting the GVRP Registration Type

Operation Command

Set GVRP registration type gvrp registration { normal | fixed | forbidden }

Set the GVRP registration type back to the default setting

manual creation, registration, and logout of VLAN are allowed on this port.

to the VLAN if a static VLAN is created on the switch and the trunk port allows VLAN passing. GVRP also adds this VLAN item to the local GVRP database, one link table for GVRP maintenance. However, GVRP cannot learn dynamic VLAN through this port.

except VLAN1 are removed and no other VLANs can be created or registered on this port.

undo gvrp registration

Example: GVRP

Configuration Example

By default, the GVRP registration type is normal.

Displaying and Debugging GVRP

After you set the GVRP registration type, execute the display command in all views to display the GVRP configuration and to verify the effect of the configuration.

Execute the debugging command in user view to debug the configuration of GVRP.

Ta bl e 12 Displaying and Debugging GVRP

Operation Command

Display GVRP statistics information display gvrp statistics [ interface interface-list ]

Display GVRP global status information

Enable GVRP packet or event debugging

Disable GVRP packet or event debugging

display gvrp status

debugging gvrp { packet | event}

undo debugging gvrp { packet | event}

Set network requirements to dynamically register and update VLAN information among switches.

Figure 2 GVRP Configuration Example

Configuring GARP/GVRP 47

E3/1/1

E4/1/1

Switch A

Switch B

Configure Switch A:

1 Set GigabitEthernet3/1/1 as a trunk port and allow all the VLANs to pass through.

[SW8800]interface GigabitEthernet3/1/1 [SW8800-GigabitEthernet3/1/1]port link-type trunk [SW8800-GigabitEthernet3/1/1]port trunk permit vlan all

2 Enable GVRP on the trunk port.

[SW8800-GigabitEthernet3/1/1]gvrp

Configure Switch B:

1 Enable GVRP globally.

[SW8800]gvrp

2 Set Gigabit Ethernet4/1/1 as a trunk port and allow all the VLANs to pass

through.

[SW8800]interface GigabitEthernet4/1/1 [SW8800-GigabitEthernet4/1/1]port link-type trunk [SW8800-GigabitEthernet4/1/1]port trunk permit vlan all

3 Enable GVRP on the trunk port.

[SW8800-GigabitEthernet4/1/1]gvrp

48 CHAPTER 3: VLAN CONFIGURATION

NETWORK PROTOCOL OPERATION

This chapter covers the following topics:

■ Configuring IP Address

■ Configuring Address Resolution Protocol (ARP)

■ DHCP Relay

■ IP Performance

Configuring IP Address

IP address is a 32-bit address represented by four octets. IP addresses are divided into five classes, A, B, C, D and E. The octets are set according to the first few bits of the first octet.

The rule for IP address classification is described as follows:

■ Class A addresses are identified with the first bit of the first octet being 0.

■ Class B addresses are identified with the first bits of the first octet being 10.

■ Class C addresses are identified with the first bits of the first octet being 110.

■ Class D addresses are identified with the first bits of the first octet being 1110.

■ Class E addresses are identified with the first bits of the first octet being 11110.

Addresses of Classes A, B and C are unicast addresses. The Class D addresses are multicast addresses and Class E addresses are reserved for future uses.

At present, IP addresses are mostly Class A, Class B and Class C. IP addresses of Classes A, B and C are composed of two parts, network ID and host ID. Their network ID lengths are different.

■ Class A IP addresses use only the first octet to indicate the network ID.

■ Class B IP addresses use the first two octets to indicate the network ID.

■ Class C IP addresses use the first three octets to indicate the network ID.

At most, there are: 28 =128 Class A addresses, 216=16384 Class B addresses and 224=2,097,152 Class C addresses.

The IP address is in dotted decimal format. Each IP address contains 4 integers in dotted decimal notation. Each integer corresponds to one byte, e.g.,10.110.50.101.

Configuring an IP Address is described in the following sections:

■ Subnet and Mask

■ Configuring an IP Address

50 CHAPTER 4: NETWORK PROTOCOL OPERATION

■ Troubleshooting an IP Address Configuration

Subnet and Mask IP protocol allocates one IP address for each network interface. Multiple IP

addresses can only be allocated to a device which has multiple network interfaces. IP addresses on a device with multiple interfaces have no relationship among themselves.

With the rapid development of the Internet, IP addresses are depleting very fast. The traditional IP address allocation method uses up IP addresses with little efficiency. The concept of mask and subnet was proposed to make full use of the available IP addresses.

A mask is a 32-bit number corresponding to an IP address. The number consists of 1s and 0s. Principally, these 1s and 0s can be combined randomly. However, the first consecutive bits are set to 1s when designing the mask. The mask is divided into two parts, the subnet address and host address. The 1 bits and the mask indicate the subnet address, and the other bits indicate the host address.

If there is no sub-net division, then the sub-net mask is the default value and the length of “1” indicates the net-id length. Therefore, for IP addresses of classes A, B and C, the default values of the corresponding sub-net mask is 255.0.0.0 for Class A, 255.255.0.0 for Class B, and 255.255.255.0 for Class C.

Configuring an IP

Address

The mask can be used to divide a Class A network containing more than 16,000,000 hosts or a Class B network containing more than 60,000 hosts into multiple small networks. Each small network is called a subnet. For example, for the Class A network address 10.110.0.0, the mask 255.255.224.0 can be used to divide the network into 8 subnets: (10.110.0.0, 10.110.32.0, 10.110.64.0, and so on). Each subnet can contain more than 8000 hosts.

The following sections describe the tasks for configuring an IP address:

■ Configure the Host IP Address and HostName for a Host

■ Configuring the IP Address of the VLAN Interface

■ Displaying and Debugging an IP Address

Configure the Host IP Address and HostName for a Host

This command creates correspondence between the name and the IP address of the host. When you use applications like Telnet, you can use the host name without having to memorize the IP address because the system translates the name to the IP address automatically.

Perform the following configuration in System view.

Ta bl e 1 Configure the Host Name and the Corresponding IP Address

Operation Command

Configure the host name and the corresponding IP address

Delete the host name and the corresponding IP address

ip host hostname ip-address

undo ip host hostname [ ip-address ]

By default, there is no host name associated to any host IP address.

Configuring IP Address 51

Configuring the IP Address of the VLAN Interface

You can configure a maximum of ten IP addresses for a VLAN interface.

Perform the following configuration in VLAN interface view.

Ta bl e 2 Configure IP Address for a VLAN Interface

Operation Command

Configure IP address for a VLAN interface ip address ip-address net-mask [ sub ]

Delete the IP address of a VLAN interface [ undo ] ip address [ ip-address { net-mask |

mask-length } [ sub ] ]

The network ID of an IP address is identified by the mask. For example, the IP address of a VLAN interface is 129.9.30.42 and the mask is 255.255.0.0. After performing the AND operation for the IP address and the mask, you can assign that device to the network segment 129.9.0.0.

Generally, it is sufficient to configure one IP address for an interface. However, you can also configure more than one IP address for an interface so that it can be connected to several subnets. Among these IP addresses, one is the primary IP address and all others are secondary.

Example: Configuring

an IP Address

By default, the IP address of a VLAN interface is null.

Displaying and Debugging an IP Address

Use the display command in all views to display the IP address configuration on interfaces, and to verify configuration.

Ta bl e 3 Display and Debug IP Address

Operation Command

Display all hosts on the network and the corresponding IP addresses

Display the configurations of each interface display ip interface vlan-interface vlan-id

display ip hosts

Configure the IP address as 129.2.2.1 and sub-net mask as 255.255.255.0 for the VLAN interface 1 of the Switch 8800.

Figure 1 IP Address Configuration Networking

Switch

Console cable

1 Enter VLAN interface 1.

[SW8800]interface vlan 1

2 Configure the IP address for VLAN interface 1.

[SW8800-vlan-interface1]ip address 129.2.2.1 255.255.255.0

52 CHAPTER 4: NETWORK PROTOCOL OPERATION

Troubleshooting an IP

Address Configuration

Configuring Address Resolution Protocol (ARP)

If the Switch 8800 cannot ping a certain host on the LAN, proceed as follows:

1 Determine which VLAN includes the port connected to the host. Check whether

the VLAN has been configured with the VLAN interface. Determine whether the IP address of the VLAN interface and the host are on the same network segment.

2 If the configuration is correct, enable ARP debugging on the switch from user

level, and check whether or not the switch can correctly send and receive ARP packets. If it can only send but not receive the ARP packets, there are probably errors at the Ethernet physical layer.

An IP address cannot be directly used for communication between network devices, because devices can only identify MAC addresses. An IP address is the address of a host at the network layer. To send data packets through the network layer to the destination host, the physical address of the host is required. So the IP address must be resolved to a physical address.

When two hosts in Ethernet communicate, they must know each other’s MAC address. Every host maintains an IP-MAC address translation table, which is known as the ARP mapping table. A series of maps between IP addresses and MAC addresses of other hosts are stored in the ARP mapping table. When a dynamic ARP mapping entry is not in use for a long time, the host will remove it from the mapping table to save memory space and shorten the search interval.

Example: IP Address

Resolution

Host A and Host B are on the same network segment. The IP address of Host A is IP_A and the IP address of Host B is IP_B. Host A wants to transmit packets to Host B. Host A checks its own ARP mapping table first to make sure that there are corresponding ARP entries of IP_B in the table. If the corresponding MAC address is found, Host A will use the MAC address in the ARP mapping table to encapsulate the IP packet in an Ethernet frame and send it to Host B. If the corresponding MAC address is not found, Host A will store the IP packet in the queue waiting for transmission, and broadcast an ARP request to attempt to resolve the MAX address of Host B.

The ARP request packet contains the IP address of Host B and the IP address and MAC address of Host A. Since the ARP request packet is broadcast, all hosts on the network segment receive the request. However, only the requested host (i.e., Host B) needs to process the request. Host B will first store the IP address and the MAC address of the request sender (Host A) from the ARP request packet in its own ARP mapping table. Host B will then generate an ARP reply packet and add the MAC address of Host B before sending it to Host A. The reply packet will be sent directly to Host A instead of being broadcast. Upon receiving the reply packet, Host A will extract the IP address and the corresponding MAC address of Host B and add them to its own ARP mapping table. Then Host A will send Host B all the packets standing in the queue.

Normally, dynamic ARP executes and automatically attempts to resolve the IP address to an Ethernet MAC address with no intervention from the administrator.

Configuring ARP The ARP mapping table can be maintained dynamically or manually. Addresses

that are mapped manually are referred to as static ARP. The user can display, add, or delete the entries in the ARP mapping table through manual commands.

Configuring Address Resolution Protocol (ARP) 53

ARP configuration includes tasks described in the following sections:

■ Manually Adding/Deleting Static ARP Mapping Entries

■ Learning Gratuitous ARPs

■ Configuring the Dynamic ARP Aging Timer

■ Displaying and Debugging ARP

Manually Adding/Deleting Static ARP Mapping Entries

Perform the following configuration in System view.

Ta bl e 4 Manually Adding/Deleting Static ARP Mapping Entries

Operation Command

Manually add a static ARP mapping entry arp static ip-address mac-address VLANID {

interface_type interface_num | interface_name

}

Manually delete a static ARP mapping entry undo arp static ip-address

Static ARP mapping entries will not time out, however dynamic ARP mapping entries time out after 20 minutes.

The ARP mapping table is empty and the address mapping is obtained through dynamic ARP by default.

Learning Gratuitous ARPs

Perform the following configuration in System view.

Ta bl e 5 Learning Gratuitous ARPs

Operation Command

Enable the switch to learn gratuitous ARPs gratuitous-arp-learning enable

Prevent the switch from learning gratuitous ARPs

undo gratuitous-arp-learning enable

By default, the switch does not learn gratuitous ARPs.

Configuring the Dynamic ARP Aging Timer

The following commands assign a dynamic ARP aging period to enable flexible configurations. When the system learns a dynamic ARP entry, its aging period is based on the currently configured value.

Perform the following configuration in system view.

Ta bl e 6 Configure the Dynamic ARP Aging Timer

Operation Command

Configure the dynamic ARP aging timer arp timer aging aging-time

Restore the default dynamic ARP aging time undo arp timer aging

By default, the aging time of the dynamic ARP aging timer is 20 minutes.

Displaying and Debugging ARP

After the previous configuration, execute display command in all views to display the operation of the ARP configuration, and to verify the effect of the

54 CHAPTER 4: NETWORK PROTOCOL OPERATION

DHCP clients

Switch

Intranet

DHCP client

DHCP server

Ethernet

configuration. Execute the debugging command in user view to debug the ARP configuration.

Ta bl e 7 Display and Debug ARP

Operation Command

Display ARP mapping table display arp [ ip-address | [ static | dynamic ] [

{ begin | include | exclude } text ] ]

Display the current setting of the dynamic ARP map aging timer

Enable ARP information debugging debugging arp { error | info | packet } Disable ARP information debugging undo debugging arp { error | info | packet }

display arp timer aging

By default, all ARP mapping entries of the Ethernet switch are displayed.

DHCP Relay Dynamic Host Configuration Protocol (DHCP) offers dynamic IP address

assignment. DHCP works in Client-Server mode. With this protocol, the DHCP Client can dynamically request configuration information and the DHCP server can configure the information for the Client.

The DHCP relay serves as conduit between the DHCP Client and the server located on different subnets. The DHCP packets can be relayed to the destination DHCP server (or Client) across network segments. The DHCP clients on different networks can use the same DHCP server. This is economical and convenient for centralized management.

Figure 2 DHCP Relay Schematic Diagram

DHCP client

Ethernet

Intranet

DHCP clients

Switch

Ethernet

DHCP server

When the DHCP Client performs initialization, it broadcasts the request packet on the local network segment. If there is a DHCP server on the local network segment (e.g. the Ethernet on the right side of the figure), then the DHCP can be configured directly without the relay. If there is no DHCP server on the local network segment, DHCP relay will process the received broadcast packets and forward them to remote DHCP servers. The server configures the clients based on the information provided in the DHCP request packet and in the server setup. Then the server transmits the configuration information to the clients through the DHCP relay, thereby, completing the dynamic configuration of the client.

DHCP Relay 55

Configuring DHCP is described in the following sections:

■ Configuring DHCP Relay

■ Troubleshooting a DHCP Relay Configuration

Configuring DHCP Relay DHCP relay configuration includes tasks described in the following sections:

■ Configuring a DHCP Server IP Address in a DHCP Server Group

■ Configuring the DHCP Server Group for the VLAN Interface

■ Configuring the Address Table Entry

■ Enabling/Disabling DHCP Security Features

■ Enabling/Disabling DHCP Pseudo-server Detection

■ Displaying and Debugging DHCP Relay

The server IP address is associated , through its DHCP server group, with a specific VLAN interface. This implementation differs from others in which the server IP is a global parameter.

Configuring a DHCP Server IP Address in a DHCP Server Group

You can set master and slave DHCP servers on a network segment to promote the reliability of the device. The master and slave DHCP servers form a DHCP server group. You can specify the IP addresses of the two servers using the following command.

Perform the following configuration in System view.

Ta bl e 8 Configure/Delete the IP Address of the DHCP Server

Operation Command

Configure the IP address for a DHCP Server dhcp-server groupNo ip ipaddress1 [

Remove all the IP addresses of the DHCP Server (set the IP addresses of the primary and secondary servers to 0).

ipaddress2 ]

undo dhcp-server groupNo

The backup server IP address cannot be configured independently, instead, it has to be configured together with the master server IP address.

By default, the IP address of the DHCP Server is not configured. The DHCP Server address must be configured before DHCP relay can be used.

Configuring the DHCP Server Group for the VLAN Interface

Perform the following configuration in VLAN interface view.

Ta bl e 9 Configure/Delete the Corresponding DHCP Server Group of VLAN Interface

Operation Command

Configure the DHCP server group for the VLAN interface

Delete the DHCP server group for the VLAN interface

dhcp-server groupNo

undo dhcp-server

56 CHAPTER 4: NETWORK PROTOCOL OPERATION

When associating a VLAN interface to a new DHCP server group, you can configure the association without disassociating it from the previous group.

By default, VLAN interfaces have no associated DHCP server group.

Configuring the Address Table Entry

To check the address of users who have valid and fixed IP addresses in the VLAN (with DHCP enabled), it is necessary to add an entry in the static address table.

Perform the following configuration in system view.

Ta bl e 10 Configure/Delete the Address Table Entry

Operation Command

Add an entry to the address table dhcp-security static ip_address mac_address

Delete an entry from the address table undo dhcp-security { ip_address | all |

Enabling/Disabling DHCP Security Features

Enabling DHCP security features starts an address check on the VLAN interface, while disabling DHCP security features cancels an address check.

{ dynamic | static }

dynamic | static }

Perform the following configuration in VLAN interface view.

Ta bl e 11 Enable/Disable DHCP Security on VLAN Interfaces

Operation Command

Enable DHCP security features address-check enable

Disable DHCP security features on VLAN interface

address-check disable

By default, DHCP security features function are disabled.

Enabling/Disabling DHCP Pseudo-server Detection

Suppose there is a DHCP server placed on a network without permission. When there is a user request for an IP address, the DHCP server will interact with the DHCP client, leading the user to get a wrong IP address. In this case, the user will be unable to access the network. Such a DHCP server is called DHCP pseudo-server.

After a DHCP pseudo-server detection-enabled, switch will record the information of the DHCP servers such as their IP addresses so that the administrator can discover the DHCP pseudo-servers.

Perform the following configuration in system view.

Ta bl e 12 Enabling and Disabling DHCP Pseudo-server Detection

Operation Command

Enable DHCP pseudo-server detection dhcp-server detect

Disable DHCP pseudo-server detection undo dhcp-server detect

By default, DHCP pseudo-server detection is disabled.

DHCP Relay 57

Displaying and Debugging DHCP Relay

Execute display command in all views to display the current DHCP Relay configuration, and to verify the effect of the configuration. Execute the

debugging command in user view to debug DHCP Relay configuration.

Ta bl e 13 Displaying and Debugging DHCP Relay

Operation Command

Display the information about the DHCP server group

Display the information about the DHCP server group corresponding to the VLAN interface.

Enable DHCP relay debugging debugging dhcp-relay

Disable DHCP relay debugging undo debugging dhcp-relay

Display address information for all the legal clients of the DHCP Server group.

display dhcp-server groupNo

display dhcp-server interface vlan-interface vlan-id

display dhcp-security [ ip_address | dynamic | static ]

Example: Configuring

DHCP Relay

Configure the VLAN interface corresponding to the user and the related DHCP server so as to use DHCP relay.

Figure 3 Networking Diagram of Configuring DHCP Relay

1.99.255.36

Server Group 1

VLAN 2

VLAN 3

Switch

VLAN 4000

VLAN 3001

1.99.255.35

IP Network

1.88.255.36

Server Group 2

1.88.255.35

1 Configure the DHCP Server IP addresses into DHCP Server Group 1.

[SW8800]dhcp-server 1 ip 1.99.255.36 1.99.255.35

2 Associate DHCP Server Group 1 with VLAN interface 2.

[SW8800-VLAN-Interface2]dhcp-server 1

3 Configure the IP address corresponding to DHCP server group 2.

[SW8800]dhcp-server 2 ip 1.88.255.36 1.88.255.35

4 Associate the DHCP Server Group 2 with VLAN interface 3.

[SW8800-VLAN-Interface3]dhcp-server 2

5 Configure the corresponding interface and gateway address of VLAN2.

[SW8800]vlan 2 [SW8800-vlan2]port GigabitEthernet 1/1/2 [SW8800]interface vlan 2 [SW8800-VLAN-Interface2]ip address 1.1.2.1 255.255.0.0

58 CHAPTER 4: NETWORK PROTOCOL OPERATION

6 Configure the corresponding interface and gateway address of VLAN3.

[SW8800]vlan 3 [SW8800-vlan3]port GigabitEthernet 1/1/3 [SW8800]interface vlan 3 [SW8800-VLAN-Interface3]ip address 21.2.2.1 255.255.0.0

7 It is necessary to configure a VLAN for the servers. The corresponding interface

VLAN of the DHCP server group 1 is configured as 4000, and that of the group 2 is configured as 3001.

[SW8800]vlan 4000 [SW8800-vlan4000]port GigabitEthernet 1/1/4 [SW8800]interface vlan 4000 [SW8800-VLAN-Interface4000]ip address 1.99.255.1 255.255.0.0 [SW8800]vlan 3001 [SW8800-vlan3001]port GigabitEthernet 1/1/5 [SW8800]interface vlan 3001 [SW8800-VLAN-Interface3001]ip address 1.88.255.1 255.255.0.0

In this example, clients on VLAN2 will receive IP addresses from the servers in DHCP server group 1 (VLAN 4000). Clients on VLAN3 will receive IP addresses from the servers in DHCP server group 2 (VLAN 3001).

Troubleshooting a DHCP

Relay Configuration

8 Show the configuration of DHCP server groups in User view.

<SW8800>display dhcp-server 1

9 Show the DHCP Server Group number corresponding to the VLAN interface in

User view.

<SW8800>display dhcp-server interface vlan-interface 2 <SW8800>display dhcp-server interface vlan-interface 3

Perform the following procedure if a user cannot apply for an IP address dynamically:

1 Use the display dhcp-server groupNo command to check if the IP address of the

corresponding DHCP server has been configured.

2 Use the display VLAN and display IP commands to check if the VLAN and the

corresponding interface IP address have been configured.

3 Ping the configured DHCP Server to ensure that the link is connected.

4 Ping the IP address of the VLAN interface of the switch to where the DHCP user is

connected from the DHCP server to make sure that the DHCP server can correctly find the route of the network segment the user is on. If the ping execution fails, check if the default gateway of the DHCP server has been configured as the address of the VLAN interface that it locates on.

5 If no problems are found in the last two steps, use the display dhcp-server

groupNo command to view the packet that has been received. If you only see the

Discover packet and there is no response packet, it means the DHCP Server has not sent the message to the Switch 8800. In this case, check if the DHCP Server has been configured properly. If the numbers of request and response packets are normal, enable the debugging dhcp-relay in User view and then use the terminal debugging command to output the debugging information to the console. In this way, you can view the detailed information of all DHCP packets on the console while applying for the IP address, thereby, conveniently locating the problem.

IP Performance IP performance configuration includes:

■ Configuring TCP Attributes

■ Displaying and Debugging IP Performance

■ Troubleshooting IP Performance

IP Performance 59

Configuring TCP

Attributes

The TCP attributes that can be configured include:

■ synwait timer: When sending the syn packets, TCP starts the synwait timer. If

response packets are not received before synwait timeout, the TCP connection will be terminated. The timeout of synwait timer ranges 2 to 600 seconds and it is 75 seconds by default.

■ finwait timer: When the TCP connection state turns from FIN_WAIT_1 to

FIN_WAIT_2, finwait timer will be started. If FIN packets are not received before finwait timer timeout, the TCP connection will be terminated. Finwait ranges 76 to 3600 seconds and it is 675 seconds by default.

■ The receiving/sending buffer size of connection-oriented Socket is in the range

from 1 to 32K bytes and is 4K bytes by default.

Perform the following configuration in System view.

Ta bl e 14 Configure TCP Attributes

Operation Command

Configure synwait timer time for TCP connection establishment

Restore synwait timer time for TCP connection establishment to default value

Configure FIN_WAIT_2 timer time of TCP tcp timer fin-timeout time-value

Restore FIN_WAIT_2 timer time of TCP to default value

Configure the Socket receiving/sending buffer size of TCP

Restore the socket receiving/sending buffer size of TCP to default value

tcp timer syn-timeout time-value

undo tcp timer syn-timeout

undo tcp timer fin-timeout

tcp window window-size

undo tcp window

Displaying and

Debugging IP

Performance

By default, the TCP finwait timer is 675 seconds, the synwait timer is 75 seconds, and the receiving/sending buffer size of connection-oriented Socket is 4K bytes.

After the previous configuration, display the operation of the IP Performance configuration in all views, and verify the effect of the configuration. Execute the

debugging command in user view to debug IP Performance configuration.

Ta bl e 15 Display and Debug IP Performance

Operation Command

Display TCP connection state display tcp status

Display TCP connection statistics data display tcp statistics

Display IP statistics information display ip statistics

Display ICMP statistics information display icmp statistics

Display the summary of the FIB display fib

60 CHAPTER 4: NETWORK PROTOCOL OPERATION

Table 15 Display and Debug IP Performance

Operation Command

Display the FIB entries matching the destination IP address (range)

Display the FIB entries that match a specific ACL

Display the FIB entries which are output from the buffer according to regular expression and related to the specific character string

Display the FIB entries matching the specific prefix list

Display the total number of FIB entries display fib statistics

Reset IP statistics information reset ip statistics

Reset TCP statistics information reset tcp statistics

display fib ip_address1 [ { mask1 | mask-length1 } [ ip_address2 { mask2 | mask-length2 } | longer ] | longer ]

display fib acl { number | name }

display fib | { { begin | include | exclude }

text }

display fib ip-prefix listname

Troubleshooting IP

Performance

If the IP layer protocol works normally, but TCP and UDP do not work normally, you can enable the corresponding debugging information output to view the debugging information.

■ Use the terminal debugging command to output the debugging information

to the console.

■ Use the debugging udp packet command to enable the UDP debugging to

trace the UDP packet. When the router sends or receives UDP packets, the content format of the packet can be displayed in real time. You can locate the problem from the contents of the packet.

The following are the UDP packet formats:

UDP output packet: Source IP address:202.38.160.1 Source port:1024 Destination IP Address 202.38.160.1 Destination port: 4296

■ Use the debugging tcp packet or debugging tcp transaction command to

enable the TCP debugging to trace the TCP packets. There are two available ways for debugging TCP.

■ Debug and trace the packets of the TCP connection that take this device as one

end.

Operations include:

<SW8800>terminal debugging <SW8800>debugging tcp packet

The TCP packets, received or sent can be checked in real time. Specific packet formats include:

TCP output packet: Source IP address:202.38.160.1 Source port:1024 Destination IP Address 202.38.160.1 Destination port: 4296 Sequence number :4185089 Ack number: 0 Flag :SYN

IPX Configuration 61

Packet length :60 Data offset: 10

■ Debug and trace the packets located in SYN, FIN or RST.

Operations include:

<SW8800>terminal debugging <SW8800>debugging tcp transact

The TCP packets received or sent can be checked in real time, and the specific packet formats are the same as those mentioned above.

IPX Configuration Internetwork Packet Exchange (IPX) protocol is a network layer protocol in the

NetWare protocol suite. It is similar to IP in the TCP/IP protocol suite. IPX functions to address, route and forward packets.

IPX is a connectionless protocol. Though an IPX packet includes a destination IPX address in addition to the data, there is no guarantee of successful delivery. Packet acknowledgement and connection control must be provided by protocols above IPX. Each IPX packet is considered an independent entity that has no logical or sequential relationship with any other IPX packets.

IPX Address Structure IPX and IP use different address structures. An IPX address comprises two parts:

the network number and the node address; it is in the format of network.node.

A network number identifies the network where a site is located. It is four bytes long and expressed by eight hexadecimal numbers. A node address identifies a node on the network. Like a MAC address, it is six bytes long and written with the bytes being separated into three 2-byte parts by “-”. The node address cannot be a broadcast or multicast address. For example, in the IPX address bc.0-0cb-47, bc (or 000000bc) is the network number and 0-0cb-47 (0000-00cb-0047) is the node address. You can also write an IPX address in the form of N.H-H-H, where N is the network number and H-H-H is the node address.

Routing Information

Protocol

IPX uses the Routing Information Protocol (RIP) to maintain and advertise dynamic routing information. With IPX enabled, the switch exchanges routing information with other neighbors through RIP to maintain an internetwork routing information database (also known as a routing table) to accommodate to the network changes. When the switch receives a packet, it looks up the routing table for the next site and if there is any, forwards the packet. The routing information can be configured statically or collected dynamically.

This chapter introduces RIP in IPX. For the RIP configurations on an IP network, refer to the routing protocol section in this manual.

Service Advertising

Protocol

The Service Advertising Protocol (SAP) advertises the services provided by servers and their addresses. It is used by IPX to maintain and advertise dynamic service information. With SAP, a server broadcasts its services when it starts and the termination of the services when it goes down.

With IPX enabled, the switch creates and maintains an internetwork service information database (or the service information table) through SAP. It helps you learn what services are available on the networks and where they are provided.

62 CHAPTER 4: NETWORK PROTOCOL OPERATION

The servers periodically broadcast their services and addresses to the networks directly connected to them. Users cannot use such information directly, however. Instead, the information is collected by the SAP agents of the switches on the networks and saved in their server information tables.

IP ROUTING PROTOCOL OPERATION

This chapter covers the following topics:

■ IP Routing Protocol Overview

■ Static Routes

■ RIP

■ OSPF

■ IS-IS

■ BGP

■ IP Routing Policy

■ Route Capacity

IP Routing Protocol Overview

Routers select an appropriate path through a network for an IP packet according to the destination address of the packet. Each router on the path receives the packet and forwards it to the next router. The last router in the path submits the packet to the destination host.

In a network, the router regards a path for sending a packet as a logical route unit, and calls it a hop. For example, in goes through 3 networks and 2 routers and the packet is transmitted through two hops and router segments. Therefore, when a node is connected to another node through a network, there is a hop between these two nodes and these two nodes are considered adjacent in the Internet. Adjacent routers are two routers connected to the same network. The number of route segments between a router and hosts in the same network count as zero. In represent the hops. A router can be connected to any physical link that constitutes a route segment for routing packets through the network.

When a switch runs a routing protocol, it can perform router functions. In this guide, a router and its icon represent a generic router or a switch running routing protocols.

Figure 1, a packet sent from Host A to Host C

Figure 1, the bold arrows

64 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Figure 1 About Hops

Route Segment

Networks can have different sizes, so, the segment lengths connected between two different pairs of routers are also different.

If a router in a network is regarded as a node and a route segment in the Internet is regarded as a link, message routing in the Internet works in a similar way as the message routing in a conventional network. Routing a message through the shortest route may not always be the optimal route. For example, routing through three LAN route segments may be much faster than a route through two WAN route segments.

Selecting Routes

Through the Routing

Ta bl e

Configuring the IP Routing Protocol Overview is described in the following sections:

■ Selecting Routes Through the Routing Table

■ Routing Management Policy

For the router, a routing table is the key to forwarding packets. Each router saves a routing table in its memory, and each entry in this table specifies the physical port of the router through which a packet is sent to a subnet or a host. The packet can reach the next router over a particular path or reach a destination host through a directly connected network.

A routing table has the following key entries:

■ A destination address — Identifies the destination IP address or the destination

network of the IP packet, which is 32 bits in length.

■ A network mask — Is made up of several consecutive 1s, which can be

expressed either in the dotted decimal format, or by the number of the consecutive 1s in the mask. Combined with the destination address, the network mask identifies the network address of the destination host or router. With the destination address and the network mask, you have the address of the network segment where the destination host or router is located. For example, if the destination address is 129.102.8.10, the address of the network where the host or the router with the mask 255.255.0.0 is located is

129.102.0.0.

IP Routing Protocol Overview 65

■ The output interface — Indicates an interface through which an IP packet

should be forwarded.

■ The next hop address — Indicates the next router that an IP packet will pass

through.

■ The priority added to the IP routing table for a route — Indicates the type of

route that is selected. There may be multiple routes with different next hops to the same destination. These routes can be discovered by different routing protocols, or they can be the static routes that are configured manually. The route with the highest priority (the smallest numerical value) is selected as the current optimal route.

Types of routes are divided into the following types, subnet routes, in which the destination is a subnet, or host routes, in which the destination is a host.

In addition, depending on whether the network of the destination host is directly connected to the router, there are the following types of routes:

■ Direct route: The router is directly connected to the network where the

destination is located.

■ Indirect route: The router is not directly connected to the network where the

destination is located.

To limit the size of the routing table, an option is available to set a default route. All the packets that fail to find a suitable table entry are forwarded through this default route.

In a complicated Internet, as shown in the following figure, the number in each network is the network address. The router R8 is connected to three networks, so it has three IP addresses and three physical ports. Its routing table is shown in Figure 2.

Figure 2 The Routing Table

15.0.0.1

14.0.0.1

15.0.0.2

15.0.0.0

14.0.0.0

12.0.0.3

16.0.0.2

13.0.0.2

14.0.0.2

13.0.0.1

12.0.0.2

16.0.0.3

16.0.0.0

13.0.0.0

12.0.0.0

16.0.0.3

13.0.0.3

13.0.0.4

10.0.0.1

11.0.0.1

11.0.0.2

10.0.0.2

10.0.0.0

11.0.0.0

Destination host location

10.0.0

11.0.0

12.0.0

13.0.0

14.0.0

15.0.0

16.0.0

Forwarding router

Directly

11.0.0.2 Directly

13.0.0.2

10.0.0.2

Port passed

1 1 3 3

Routing Management

Policy

12.0.0.1

The Switch 8800 supports the configuration of a series of dynamic routing protocols such as RIP, OSPF, as well as static routes. The static routes configured by

66 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

the user are managed together with the dynamic routes as detected by the routing protocol. The static routes and the routes learned or configured by routing protocols can be shared with each other.

Routing protocols (as well as the static configuration) can generate different routes to the same destination, but not all these routes are optimal. In fact, at a certain moment, only one routing protocol can determine a current route to a single destination. Thus, each routing protocol (including the static configuration) has a set preference, and when there are multiple routing information sources, the route discovered by the routing protocol with the highest preference becomes the current route. Routing protocols and the default preferences (the smaller the value, the higher the preference) of the routes that they learn are shown in Ta bl e 1.

Ta bl e 1 Routing Protocols and the Default Preferences for Routes

Routing protocol or route type

DIRECT 0

OSPF 10

ISIS 15

STATIC 60

RIP 100

OSPF ASE 150

OSPF NSSA 150

IBGP 256

EBGP 256

UNKNOWN 255

The preference of the corresponding route

In the table, 0 indicates a direct route, and 255 indicates any route from an unreliable source.

Except for direct routing and BGP (IBGP and EBGP), the preferences of various dynamic routing protocols can be manually configured to meet the user requirements. The preferences for individual static routes can be different.

Supporting Load Sharing and Route Backup

The Switch 8800 supports load sharing and route backup.

Load sharing is supported by configuring multiple routes that reach the same destination and use the same precedence. The same destination can be reached by multiple different paths, whose precedences are equal. When there is no route that can reach the same destination with a higher precedence, the multiple routes will be adopted by IP, which will forward the packets to the destination by these paths to implement load sharing.

Route backup allows the system to automatically switch to a backup route when main route has failed to improve network reliability.

To achieve route backup, the user can configure multiple routes to the same destination according to actual situation. One of the routes has the highest precedence and is called as main route. The other routes have descending precedence and are called backup routes. Normally, the router sends data by the

Static Routes 67

main route. When the line fails, the main route hides itself and the router chooses one from the remaining routes as a backup route whose precedence is higher than others' to send data. When the main route recovers, the router restores it and re-selects a route. As the main route has the highest precedence, the router chooses the main route to send data. This process is the automatic switchover from the backup route to the main route.

For the same destination, a specified routing protocol may find multiple different routes. If the routing protocol has the highest precedence among all active routing protocols, these multiple routes will be regarded as currently valid routes. Thus, load sharing of IP traffic is ensured in terms of routing protocols. The Switch 8800 supports four routes to implement load sharing.

Routes Shared Between Routing Protocols

As the algorithms of various routing protocols are different, different protocols can generate different routes. This situation creates the problem of how to resolve different routes being generated by different routing protocols. The Switch 8800 supports an operation to import the routes generated by one routing protocol into another routing protocol. Each protocol has its own route redistribution mechanism. For details, refer to

“Enabling RIP to Import Routes of Other Protocols”, “Configuring OSPF to Import the Routes of Other Protocols”, or “Importing Routing Information Discovered by Other Routing Protocols”.

Static Routes A static route is a route that is manually configured by the network administrator.

You can set up an interconnected network using static routes. However, if a fault occurs in the network, the static route cannot change automatically to steer packets away from the fault without the help of the administrator.

In a relatively simple network, you only need to configure static routes to make the router work normally. The proper configuration and usage of the static route can improve network performance and ensure bandwidth for important applications.

The following routes are static routes:

■ Reachable route — The normal route in which the IP packet is sent to the next

hop towards the destination. It is a common type of static route.

■ Unreachable route — When a static route to a destination has the reject

attribute, all the IP packets to this destination are discarded, and the originating host is informed that the destination is unreachable.

■ Blackhole route — When a static route to a destination has the blackhole

attribute, all the IP packets to this destination are discarded, and the originating host is not informed.

The attributes reject and blackhole are usually used to control the range of reachable destinations of this router, and to help troubleshoot the network.

Default Route

A default route is also a static route. A default route is used only when no suitable routing table entry is found. In a routing table, the default route is in the form of the route to the network 0.0.0.0 (with the mask 0.0.0.0). You can determine whether a default route has been set by viewing the output of the display ip

routing-table command. If the destination address of a packet fails to match any

68 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

entry of the routing table, the router selects the default route to forward this packet. If there is no default route and the destination address of the packet fails to match any entry in the routing table, the packet is discarded, and an Internet Control Message Protocol (ICMP) packet is sent to the originating host to indicate that the destination host or network is unreachable.

In a typical network that consists of hundreds of routers, if you used multiple dynamic routing protocols without configuring a default route then significant bandwidth would be consumed. Using the default route can provide appropriate bandwidth, but not high bandwidth, for communications between large numbers of users.

Configuring Static Routes is described in the following sections:

■ Configuring Static Routes

■ Troubleshooting Static Routes

Configuring Static

Routes

Static route configuration tasks are described in the following sections:

■ Configuring a Static Route

■ Configuring a Default Route

■ Deleting All Static Routes

■ Displaying and Debugging Static Routes

Configuring a Static Route

Perform the following configurations in system view.

Ta bl e 2 Configuring a Static Route

Operation Command

Add a static route ip route-static ip-address {mask |

mask-length } { interface-name | gateway-address } [ preference value ] [

reject | blackhole ]

Delete a static route undo ip route-static ip-address {mask |

mask-length } { interface-name | gateway-address} [ preference value ]

The parameters are explained as follows:

■ IP address and mask

The IP address and mask use a decimal format. Because the 1s in the 32-bit mask must be consecutive, the dotted decimal mask can also be replaced by the mask-length which refers to the digits of the consecutive 1s in the mask.

■ Transmitting interface or next hop address

When you configure a static route, you can specify either the interface-type port-number to designate a transmitting interface, or the gateway-address to decide the next hop address, depending on the actual conditions.

You can specify the transmitting interfaces in the cases below:

■ For the interface that supports resolution from the network address to the link

layer address (such as the Ethernet interface that supports ARP), when ip-address and mask (or mask-length) specifies a host address, and this

Static Routes 69

destination address is in the directly connected network, the transmitting interface can be specified.

■ For a P2P interface, the address of the next hop defines the transmitting

interface because the address of the opposite interface is the address of the next hop of the route.

In fact, for all routing items, the next hop address must be specified. When the IP layer transmits a packet, it first searches the matching route in the routing table, depending on the destination address of the packet. Only when the next hop address of the route is specified, can the link layer find the corresponding link layer address, and then forward the packet.

■ For different configurations of preference-value, you can flexibly apply the

routing management policy.

■ The reject and blackhole attributes indicate the unreachable route and the

blackhole route.

Configuring a Default Route

Perform the following configurations in system view.

Ta bl e 3 Configuring a Default Route

Operation Command

Configure a default route ip route-static 0.0.0.0 { 0.0.0.0 | 0 } {

interface-name | gateway-address } [ preference value ] [ reject | blackhole ]

Delete a default route undo ip route-static 0.0.0.0 { 0.0.0.0 | 0 } {

interface-name | gateway-address } ]

Parameters for default route are the same as for static route.

Deleting All Static Routes

You can use the undo ip route-static command to delete one static route. The Switch 8800 also provides the delete static-route all command for you to delete all static routes at one time, including the default routes.

Perform the following configuration in system view.

Ta bl e 4 Deleting All Static Routes

Operation Command

Delete all static routes delete static-routes all

Displaying and Debugging Static Routes

After you configure static and default routes, execute the display command in all views, to display the static route configuration, and to verify the effect of the configuration.

Ta bl e 5 Displaying and Debugging the Routing Table

Operation Command

View routing table summary display ip routing-table

View routing table details display ip routing-table verbose

View the detailed information of a specific route

display ip routing-table ip-address

70 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Table 5 Displaying and Debugging the Routing Table

Operation Command

View the route filtered through specified basic access control list (ACL)

View the route information that through specified ip prefix list

View the routing information found by the specified protocol

View the tree routing table display ip routing-table radix

View the integrated routing information display ip routing-table statistics

display ip routing-table acl { acl-number | acl-name } [ verbose ]

display ip routing-table ip-prefix ip-prefix-number [ verbose ]

display ip routing-table protocol protocol [ inactive | verbose ]

Example: Typical Static

Route Configuration

As shown in the Figure 3, the masks of all the IP addresses in the figure are

255.255.255.0. All the hosts or switches must be interconnected in pairs, by configuring static routes.

Figure 3 Static Route Configuration

Host 1.1.5.1

1.1.5.2/24

1.1.3.1/24

1.1.2.1/24

1.1.1.2/24

Switch A

Host 1.1.1.1

Switch C

1.1.3.2/24

Switch B

1.1.4.1/24

Host 1.1.4.2

1 Configure the static route for Switch A:

[Switch A]ip route-static 1.1.3.0 255.255.255.0 1.1.2.2 [Switch A]ip route-static 1.1.4.0 255.255.255.0 1.1.2.2 [Switch A]ip route-static 1.1.5.0 255.255.255.0 1.1.2.2

2 Configure the static route for Switch B:

[Switch B]ip route-static 1.1.2.0 255.255.255.0 1.1.3.1 [Switch B]ip route-static 1.1.5.0 255.255.255.0 1.1.3.1 [Switch B]ip route-static 1.1.1.0 255.255.255.0 1.1.3.1

3 Configure the static route for Switch C:

[Switch C]ip route-static 1.1.1.0 255.255.255.0 1.1.2.1 [Switch C]ip route-static 1.1.4.0 255.255.255.0 1.1.3.2

4 Configure the default gateway of the Host A to be 1.1.5.2

5 Configure the default gateway of the Host B to be 1.1.4.1

RIP 71

6 Configure the default gateway of the Host C to be 1.1.1.2

Using this procedure, all the hosts or switches in Figure 3 can be interconnected in pairs.

Troubleshooting Static

Routes

The Switch 8800 is not configured with any dynamic routing protocols enabled. Both the physical status and the link layer protocol status of the interface are enabled, but the IP packets cannot be forwarded normally.

■ Use the display ip routing-table protocol static command to view

whether the corresponding static route is correctly configured.

■ Use the display ip routing-table command to view whether the

corresponding route is valid.

RIP Routing Information Protocol (RIP) is a simple, dynamic routing protocol, that is

Distance-Vector (D-V) algorithm-based. It uses hop counts to measure the distance to the destination host, which is called routing cost. In RIP, the hop count from a router to its directly connected network is 0. The hop count to a network which can be reached through another router is 1, and so on. To restrict the time to converge, RIP prescribes that the cost value is an integer that ranges from 0 to 15. The hop count equal to or exceeding 16 is defined as infinite, or the destination network or host is unreachable.

RIP exchanges routing information using UDP packets. RIP sends a routing refresh message every 30 seconds. If no routing refresh message is received from one network neighbor in 180 seconds, RIP tags all routes of the network neighbor as unreachable. If no routing refresh message is received from one network neighbor in 300 seconds, RIP removes the routes of the network neighbor from the routing table. RIP v2 has the MD5 cipher authentication function while RIP v1 does not.

To improve performance and avoid routing loops, RIP supports split horizon, poison reverse, and allows for importing routes discovered by other routing protocols.

Each router that is running RIP manages a route database, which contains routing entries to all the reachable destinations in the network. These routing entries contain the following information:

■ Destination address — The IP address of a host or network.

■ Next hop address — The address of the next router that an IP packet will pass

through to reach the destination.

■ Output interface — The interface through which the IP packet should be

forwarded.

■ Cost — The cost for the router to reach the destination, which should be an

integer in the range of 0 to 15.

■ Timer — The length of time from the last time that the routing entry was

modified until now. The timer is reset to 0 whenever a routing entry is modified.

■ Route tag — The indication whether the route is generated by an interior

routing protocol, or by an exterior routing protocol.

72 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

The whole process of RIP startup and operation can be described as follows:

1 If RIP is enabled on a router for the first time, the router broadcasts a request

packet to adjacent routers. When they receive the request packet, adjacent routers (on which RIP is also enabled) respond to the request by returning response packets containing information about their local routing tables.

2 After receiving the response packets, the router that sent the request modifies its

own routing table.

3 RIP broadcasts its routing table to adjacent routers every 30 seconds. The adjacent

routers maintain their own routing tables after receiving the packets and elect an optimal route, then advertise the modification information to their adjacent network to make the updated route globally available. Furthermore, RIP uses timeout mechanism to handle timed-out routes to ensure the timeliness and validity of the routes. With these mechanisms, RIP, an interior routing protocol, enables the router to learn the routing information of the entire network.

RIP has become one of the most popular standards of transmitting router and host routes. It can be used in most campus networks and regional networks that are simple, yet extensive. RIP is not recommended for larger and more complicated networks.

Configuring RIP is described in the following sections:

■ Configuring RIP

■ Troubleshooting RIP

Configuring RIP Only after RIP is enabled can other functional features be configured. But the

configuration of the interface-related functional features is not dependent on whether RIP has been enabled.

After RIP is disabled, the interface-related features also become invalid.

The RIP configuration tasks are described in the following sections:

■ Enabling RIP and Entering the RIP View

■ Enabling the RIP Interface

■ Configuring Unicast RIP Messages

■ Specifying the RIP Version

■ Configuring RIP Timers

■ Configuring RIP-1 Zero Field Check of the Interface Packet

■ Specifying the Operating State of the Interface

■ Disabling Host Route

■ Enabling RIP-2 Route Aggregation

■ Setting RIP-2 Packet Authentication

■ Configuring Split Horizon

■ Enabling RIP to Import Routes of Other Protocols

■ Configuring the Default Cost for the Imported Route

■ Setting the RIP Preference

RIP 73

■ Setting Additional Routing Metrics

■ Configuring Route Filtering

■ Displaying and Debugging RIP

Enabling RIP and Entering the RIP View

Perform the following configurations in system view.

Ta bl e 6 Enabling RIP and Entering the RIP View

Operation Command

Enable RIP and enter the RIP view rip

Disable RIP undo rip

By default, RIP is not enabled.

Enabling the RIP Interface

For flexible control of RIP operation, you can specify the interface and configure the network where it is located in the RIP network, so that these interfaces can send and receive RIP packets.

Perform the following configurations in RIP view.

Ta bl e 7 Enabling RIP Interface

Operation Command

Enable RIP on the specified network interface network network-address

Disable RIP on the specified network interface undo network network-address

After the RIP interface is enabled, you should also specify its operating network segment, because RIP only operates on the interface when the network segment has been specified. RIP does not receive or send routes for an interface that is not on the specified network, and does not forward its interface route.

The network-address parameter is the address of the enabled or disabled network, and it can also be configured as the IP network address of the appropriate interfaces.

When a network command is used for an address, the effect is to enable the interface of the network with the address. For example, for network

129.102.1.1, you can see network 129.102.0.0 using either the display current-configuration command or the display rip command.

Configuring Unicast RIP Messages

RIP is a broadcast protocol. To exchange route information with the non-broadcast network, the unicast transmission mode must be adopted.

Perform the following configuration in the RIP view.

Ta bl e 8 Configuring Unicast RIP Messages

Operation Command

Configure unicast RIP messages peer ip-address

Cancel unicast RIP messages undo peer ip-address

74 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

By default, RIP does not send messages to unicast addresses.

Usually, this command is not recommended because the opposite side does not need to receive two of the same messages at a time. It should be noted that the peer command should also be restricted by the rip work, rip output, rip input and network commands.

Specifying the RIP Version

RIP has two versions, RIP-1 and RIP-2. You can specify the version of the RIP packet processed by the interface.

RIP-1 broadcasts the packets. RIP-2 can transmit packets by both broadcast and multicast. By default, multicast is adopted for transmitting packets. In RIP-2, the default multicast address is 224.0.0.9. The advantage of transmitting packets in the multicast mode is that the hosts in the same network that do not run RIP, do not receive RIP broadcast packets. In addition, this mode prevents the hosts that are running RIP-1 from incorrectly receiving and processing the routes with subnet mask in RIP-2. When an interface is running RIP-2, it can also receive RIP-1 packets.

Perform the following configuration in VLAN interface view.

Ta bl e 9 Specifying RIP Version of the Interface

Operation Command

Specify the interface version as RIP-1 rip version 1

Specify the interface version as RIP-2 rip version 2 [ broadcast | multicast ]

Restore the default RIP version running on the interface

undo rip version { 1 | 2 }

By default, the interface receives and sends RIP-1 packets. It transmits packets in multicast mode when the interface RIP version is set to RIP-2.

Configuring RIP Timers

As stipulated in RFC1058, RIP is controlled by three timers, period update, timeout, and garbage-collection:

■ Period update is triggered periodically to send all RIP routes to all the

neighbors.

■ If a RIP route has not been updated when the timeout timer expires, the route

will be considered unreachable.

■ If the garbage-collection timer times out before the unreachable route is

updated by the update packets from the neighbors, the route will be deleted completely from the routing table.

Modification of these timers can affect the convergence speed of RIP.

RIP 75

Perform the following configuration in RIP view.

Ta bl e 10 Configuring RIP Timers

Operation Command

Configure RIP timers timers { update update-timer-length |

timeout timeout-timer-length }*

Restore the default settings of RIP undo timers { update | timeout } *

The modification of RIP timers takes effect immediately.

By default, the values of period update and timeout timers are 30 seconds and 180 seconds. The value of garbage-collection timer is four times that of period update timer, 120 seconds.

In fact, you may find that the timeout time of garbage-collection timer is not fixed. If period update timer is set to 30 seconds, garbage-collection timer might range from 90 to 120 seconds.

Before RIP completely deletes an unreachable route from the routing table, it advertises the route by sending four update packets with route metric of 16, to let all the neighbors knows that the route is unreachable. Routes do not always become unreachable when a new period starts so the actual value of the garbage-collection timer is 3 to 4 times the value of the period update timer.

You must consider network performance when adjusting RIP timers, and configure all the routes that are running RIP, to avoid unnecessary traffic or network oscillation.

Configuring RIP-1 Zero Field Check of the Interface Packet

According to the RFC1058, some fields in the RIP-1 packet must be 0. When an interface version is set to RIP-1, the zero field check must be performed on the packet. If the value in the zero field is not zero, processing is refused. There are no zero fields in RIP-2 packets so configuring a zero field check is invalid for RIP-2.

Perform the following configurations in RIP view.

Ta bl e 11 Configuring Zero Field Check of the Interface Packet

Operation Command

Configure zero field check on the RIP-1 packet checkzero

Disable zero field check on the RIP-1 packet undo checkzero

By default, RIP-1 performs zero field check on the packet.

Specifying the Operating State of the Interface

In the VLAN interface view, you can specify whether RIP update packets are sent and received on the interface. In addition, you can specify whether an interface sends or receives RIP update packets.

76 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Perform the following configuration in VLAN interface view.

Ta bl e 12 Specifying the Operating State of the Interface

Operation Command

Enable the interface to run RIP rip work

Disable RIP on the interface undo rip work

Enable the interface to receive RIP update packets

Disable receipt of RIP update packets on the interface

Enable the interface to send RIP update packets

Disable transmission of RIP packets on the interface

The rip work command is functionally equivalent to both rip input and rip output commands.

By default, all interfaces except loopback interfaces both receive and transmit RIP update packets.

rip input

undo rip input

rip output

undo rip output

Disabling Host Route

In some cases, the router can receive many host routes from the same segment, and these routes are of little help in route addressing but consume a lot of network resources. Routers can be configured to reject host routes by using undo host-route command.

Perform the following configurations in RIP view.

Ta bl e 13 Disabling Host Routes

Operation Command

Enable receiving host routes host-route

Disable receiving host routes undo host-route

By default, the router receives the host route.

Enabling RIP-2 Route Aggregation

Route aggregation means that different subnet routes in the same natural network can be aggregated into one natural mask route for transmission when they are sent to other outside networks. Route aggregation can be performed to reduce the routing traffic on the network, as well as to reduce the size of the routing table.

RIP-1 only sends the routes with natural mask, that is, it always sends routes in the route aggregation form.

RIP-2 supports subnet mask and classless inter-domain routing. To advertise all the subnet routes, the route aggregation function of RIP-2 can be disabled.

RIP 77

Perform the following configurations in RIP view.

Ta bl e 14 Enabling Route Aggregation

Operation Command

Enable the automatic aggregation function of RIP-2

Disable the automatic aggregation function of RIP-2

summary

undo summary

By default, RIP-2 uses the route aggregation function.

Setting RIP-2 Packet Authentication

RIP-1 does not support packet authentication. However, you can configure packet authentication on RIP-2 interfaces.

RIP-2 supports two authentication modes:

■ Simple authentication — This mode does not ensure security. The key is not

encrypted and can be seen in a network trace so simple authentication should not be applied when there are high security requirements

■ MD5 authentication — This mode uses two packet formats: One format

follows RFC1723 (RIP Version 2 Carrying Additional Information); the other format follows RFC2082 (RIP-2 MD5 Authentication).

Perform the following configuration in VLAN interface view

Ta bl e 15 Setting RIP-2 Packet Authentication

Operation Command

Configure RIP-2 simple authentication key rip authentication-mode simple

password-string

Configure RIP-2 MD5 authentication with packet type following RFC 1723

Configure RIP-2 MD5 authentication with packet type following RFC 2082

Set the packet format type of RIP-2 MD5 authentication

Cancel authentication of RIP-2 packet undo rip authentication-mode

rip authentication-mode { simple password | md5 { usual key-string | nonstandard key-string key-id } }

The usual packet format follows RFC1723 and nonstandard follows RFC2082.

Configuring Split Horizon

Split horizon means that the route received through an interface will not be sent through this interface again. The split horizon algorithm can reduce the generation of routing loops, but in some special cases, split horizon must be disabled to obtain correct advertising at the cost of efficiency. Disabling split horizon has no effect on the P2P connected links but is applicable on the Ethernet.

78 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Perform the following configuration in VLAN interface view.

Ta bl e 16 Configuring Split Horizon

Operation Command

Enable split horizon rip split-horizon

Disable split horizon undo rip split-horizon

By default, split horizon of the interface is enabled.

Enabling RIP to Import Routes of Other Protocols

RIP allows users to import the route information of other protocols into the routing table.

RIP can import direct, static, OSPF, BGP, and IS-IS routes.

BGP and IS-IS require the advanced version of the software on the Switch 8800.

Perform the following configurations in RIP view.

Ta bl e 17 Enabling RIP to Import Routes of Other Protocols

Operation Command

Enable RIP to import routes of other protocols import-route protocol [ cost value ]

Disable route imports from other protocols undo import-route protocol

[route-policy route-policy-name ]

By default, RIP does not import the route information of other protocols.

Configuring the Default Cost for the Imported Route

When you use the import-route command to import the routes of other protocols, you can specify their cost. If you do not specify the cost of the imported route, RIP will set the cost to the default cost, specified by the default cost parameter.

Perform the following configurations in RIP view.

Ta bl e 18 Configuring the Default Cost for the Imported Route

Operation Command

Configure default cost for the imported route default cost value

Restore the default cost of the imported route.

undo default cost

By default, the cost value for the RIP imported route is 1.

Setting the RIP Preference

Each routing protocol has its own preference by which the routing policy selects the optimal one from the routes of different protocols. The greater the preference value, the lower the preference. The preference of RIP can be set manually.

RIP 79

Perform the following configurations in RIP view.

Ta bl e 19 Setting the RIP Preference

Operation Command

Set the RIP Preference preference value

Restore the default value of RIP preference undo preference

By default, the preference of RIP is 100.

Setting Additional Routing Metrics

The additional routing metric, is the input or output routing metric added to a RIP route. It does not change the metric value of the route in the routing table, but adds a specified metric value when the interface receives or sends a route.

Perform the following configuration in VLAN interface view.

Ta bl e 20 Setting Additional Routing Metric

Operation Command

Set the additional routing metric of the route when the interface receives an RIP packet

Disable the additional routing metric of the route when the interface receives an RIP packet

Set the additional routing metric of the route when the interface sends an RIP packet

Disable the additional routing metric of the route when the interface sends an RIP packet

rip metricin value

undo rip metricin

ip metricout value

undo rip metricout

By default, the additional routing metric added to the route when RIP sends the packet is 1. The additional routing metric when RIP receives the packet is 0.

Configuring Route Filtering

The router provides the route filtering function. You can configure the filter policy rules by specifying the ACL and ip-prefix for route redistribution and distribution. To import a route, the RIP packet of a specific router can also be received by designating a neighbor router.

Perform the following configurations in RIP view.

Ta bl e 21 Configuring RIP to Filter Routes

Operation Command

Configure filtering the received routing information distributed by the specified address

Cancel filtering the received routing information distributed by the specified address

Configure filtering the received global routing information

Cancel filtering the received global routing information

filter-policy gateway ip-prefix-name import

undo filter-policy gateway ip-prefix-name import

filter-policy { acl-number | ip-prefix ip-prefix-name } import

undo filter-policy { acl-number | ip-prefix ip-prefix-name } import

80 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

By default, RIP does not filter received and distributed routing information.

Displaying and Debugging RIP

After configuring RIP, execute the display command in all views to display the RIP configuration, and to verify the effect of the configuration. Execute the debugging command in user view to debug the RIP module. Execute the reset command in RIP view to reset the system configuration parameters of RIP.

Ta bl e 22 Displaying and Debugging RIP

Operation Command

Display the current RIP state and configuration information.

Enable the RIP debugging information debugging rip packets

Enable the debugging of RIP receiving packet. debugging rip receive

Enable the debugging of RIP sending packet. debugging rip send

Restore the default RIP settings reset

display rip

Example: Typical RIP

Configuration

As shown in Figure 4, the Switch C connects to the subnet 117.102.0.0 through the Ethernet port. The Ethernet ports of Switch A and Switch B are connected to the network 155.10.1.0 and 196.38.165.0. Switch C, Switch A, and Switch B are connected by Ethernet 110.11.2.0. Correctly configure RIP to ensure that Switch C, Switch A, and Switch B can interconnect.

Figure 4 RIP Configuration

Network address:

155.10.1.0/24

Switch A

Network address:

110.11.2.2/24

Switch B

Network address:

196.38.165.0/24

Ethernet

Switch C

Network address:

117.102.0.0/16

Interface address:

155.10.1.1/24

Interface address:

110.11.2.1/24

Interface address:

117.102.0.1/16

Interface address:

196.38.165.1/24

The following configuration only shows the operations related to RIP. Before performing the following configuration, verify that the Ethernet link layer works normally.

1 Configure RIP on Switch A:

[Switch A]rip [Switch A-rip]network 110.11.2.0 [Switch A-rip]network 155.10.1.0

2 Configure RIP on Switch B:

[Switch B]rip [Switch B-rip]network 196.38.165.0

OSPF 81

[Switch B-rip]network 110.11.2.0

3 Configure RIP on Switch C:

[Switch C]rip [Switch C-rip]network 117.102.0.0 [Switch C-rip]network 110.11.2.0

Troubleshooting RIP The Switch 8800 cannot receive update packets when the physical connection to

the peer routing device is normal.

■ RIP does not operate on the corresponding interface (for example, if the undo

rip work command is executed) or this interface is not enabled through the network command.

■ The peer routing device is configured for multicast mode (for example, the rip

version 2 multicast command is executed) but the multicast mode has not

been configured on the corresponding interface of the local switch.

OSPF Open Shortest Path First (OSPF) is an Interior Gateway Protocol (IGP). At present,

OSPF version 2 (RFC2328) is used, which has the following features:

■ Scope — Supports networks of various sizes and can support several hundred

routers

■ Fast convergence — Transmits the update packets instantly after the network

topology changes so the change is synchronized in the AS

■ Loop-free — Calculates routes using the shortest path tree algorithm,

according to the collected link states so that no loop routes are generated from the algorithm itself

■ Area partition — Allows the network of AS to be divided into different areas

for management convenience, so that the routing information that is transmitted between the areas is further abstracted to reduce network bandwidth consumption

■ Equal-cost multi-route — Supports multiple equal-cost routes to a destination

■ Routing hierarchy — Supports a four-level routing hierarchy that prioritizes

routes into intra-area, inter-area, external type-1, and external type-2 routes.

■ Authentication — Supports the interface-based packet authentication to

guarantee the security of the route calculation

■ Multicast transmission — Uses multicast addresses to send updates.

Configuring OSPF is described in the following sections:

■ Calculating OSPF Routes

■ Configuring OSPF

■ Troubleshooting OSPF

Calculating OSPF Routes The OSPF protocol calculates routes in the following way:

■ Each OSPF-capable router maintains a Link State Database (LSD), which

describes the topology of the entire AS. According to the network topology around itself, each router generates a Link State Advertisement (LSA). The routers on the network transmit the LSAs among themselves by transmitting

82 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

the protocol packets to each other. Thus, each router receives the LSAs of other routers and all these LSAs constitute its LSD.

■ LSA describes the network topology around a router, so the LSD describes the

network topology of the entire network. Routers can easily transform the LSD to a weighted directed graph, which actually reflects the topology of the whole network. All the routers have the same graph.

■ A router uses the SPF algorithm to calculate the shortest path tree which shows

the routes to the nodes in the autonomous system. In this tree, the router is the root. The external routing information is a leaf node. A router that advertises the routes, also tags them and records the additional information of the autonomous system. Therefore, the routing tables obtained from different routers are different.

OSPF supports interface-based packet authentication to guarantee the security of route calculation. OSPF also transmits and receives packets by IP multicast.

OSPF Packets

OSPF uses five types of packets:

■ Hello Packet

The Hello packet is the most common packet sent by the OSPF protocol. A router periodically sends it to its neighbor. It contains the values of some timers, DR, BDR and the known neighbor.

■ Database Description (DD) Packet

When two routers synchronize their databases, they use the DD packets to describe their own Link State Databases (LSDs), including the digest of each LSA. The digest refers to the HEAD of an LSA, which can be used to uniquely identify the LSA. Synchronizing databases with DD packets reduces the traffic size transmitted between the routers, since the HEAD of an LSA only occupies a small portion of the overall LSA traffic. With the HEAD, the peer router can judge whether it has already received the LSA.

■ Link State Request (LSR) Packet

After exchanging the DD packets, the two routers know which LSAs of the peer routers are missing from the local LSD’s. In this case, they send LSR packets to the peers, requesting the missing LSAs. The packets contain the digests of the missing LSAs.

■ Link State Update (LSU) Packet

The LSU packet is used to transmit the needed LSAs to the peer router. It contains a collection of multiple LSAs (complete contents).

■ Link State Acknowledgment (LSAck) Packet

The packet is used for acknowledging received LSU packets. It contains the HEAD(s) of LSA(s) requiring acknowledgement.

Basic Concepts Related to OSPF

■ Router ID

To run OSPF, a router must have a router ID. If no ID is configured, the system automatically selects an IP address from the IP addresses of the current interface as the router ID.

OSPF 83

■ Designated Router (DR)

In a broadcast network, in which all routers are directly connected, any two routers must establish adjacency to broadcast their local status information to the whole AS. In this situation, every change that a router makes results in multiple transmissions, which is not only unnecessary but also wastes bandwidth. To solve this problem, OSPF defines a “designated router” (DR). All routers send information only to the DR for broadcasting the network link states to the network. This reduces the number of router adjacent relations on the multi-access network.

When the DR is not manually specified, the DR is elected by all the routers in the segment. See

■ Backup Designated Router (BDR)

“Setting the Interface Priority for DR Election”

If the DR fails, a new DR must be elected and synchronized with the other routers on the segment. This process takes a relatively long time, during which the route calculation is incorrect. To shorten the process, OSPF creates a BDR as backup for the DR. A new DR and BDR are elected in the meantime. The adjacencies are also established between the BDR and all the routers on the segment, and routing information is also exchanged between them. After the existing DR fails, the BDR becomes a DR immediately.

■ Area

If all routers on a large network are running OSPF, the large number of routers results in an enormous LSD, which consumes storage space, complicates the SPF algorithm, and adds CPU. Furthermore, as a network grows larger, the topology becomes more likely to change. Hence, the network is always in “turbulence”, and a large number of OSFP packets are generated and transmitted in the network. This shrinks network bandwidth. In addition, each change causes all the routers on the network to recalculate the routes.

OSPF solves this problem by dividing an AS into different areas. Areas logically group the routers, which form the borders of each area. Thus, some routers may belong to different areas. A router that connects the backbone area and a non-backbone area is called an area border router (ABR). An ABR can connect to the backbone area physically or logically.

■ Backbone Area

After the area division of OSPF, one area is different from all the other areas. Its area-id is 0 and it is usually called the backbone area.

■ Virtual link

Since all the areas should be connected logically, virtual link is adopted so that the physically separated areas can still maintain logical connectivity.

■ Route summary

An AS is divided into different areas that are interconnected through OSPF ABRs. The routing information between areas can be reduced by use of a route summary. Thus, the size of routing table can be reduced and the calculation speed of the router can be improved. After finding an intra-area route of an area, the ABR looks in the routing table and encapsulates each OSPF route into an LSA and sends it outside the area.

84 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Configuring OSPF You must first enable OSPF then specify the interface and area ID before

configuring other functions. However, the configuration of functions that are related to the interface does not depend on whether OSPF is enabled. However, if OSPF is disabled, the OSPF-related interface parameters become invalid.

OSPF configuration includes tasks that are described in the following sections:

■ Enabling OSPF and Entering OSPF View

■ Entering OSPF Area View

■ Specifying the Interface

■ Configuring Router ID

■ Configuring the Network Type on the OSPF Interface

■ Configuring the Cost for Sending Packets on an Interface

■ Setting the Interface Priority for DR Election

■ Setting the Peer

■ Setting the Interval of Hello Packet Transmission

■ Setting a Dead Timer for the Neighboring Routers

■ Configuring an Interval Required for Sending LSU Packets

■ Setting an Interval for LSA Retransmission Between Neighboring Routers

■ Setting a Shortest Path First (SPF) Calculation Interval for OSPF

■ Configuring the OSPF STUB Area

■ Configuring NSSA of OSPF

■ Configuring the Route Summarization of OSPF Area

■ Configuring OSPF Virtual Link

■ Configuring Summarization of Imported Routes by OSPF

■ Configuring the OSPF Area to Support Packet Authentication

■ Configuring OSPF Packet Authentication

■ Configuring OSPF to Import the Routes of Other Protocols

■ Configuring Parameters for OSPF to Import External Routes

■ Configuring OSPF to Import the Default Route

■ Setting OSPF Route Preference

■ Configuring OSPF Route Filtering

■ Configuring Filling the MTU Field When an Interface Transmits DD Packets

■ Disabling the Interface to Send OSPF Packets

■ Configuring OSPF and Network Management System (NMS)

■ Resetting the OSPF Process

■ Displaying and Debugging OSPF

OSPF 85

Enabling OSPF and Entering OSPF View

Perform the following configurations in system view.

Ta bl e 23 Enabling the OSPF Process

Operation Command

Enable the OSPF process ospf [ process-id [[ router-id router-id ]]

Disable the OSPF process undo ospf [ process-id ]

By default, OSPF is not enabled.

Entering OSPF Area View

Perform the following configurations in OSPF view.

Ta bl e 24 Entering OSPF Area View

Operation Command

Enter an OSPF area view area area-id

Delete a designated OSPF area undo area area-id

Specifying the Interface

OSPF divides the AS into different areas. You must configure each OSPF interface to belong to a particular area, identified by an area ID. The areas transfer routing information between them through the ABRs.

In addition, parameters of all the routers in the same area should be identical. Therefore, when configuring the routers in the same area, please note that most configurations should be based on the area. An incorrect configuration can disable the neighboring routers from transmitting information, and lead to congestion or self-loop of the routing information.

Perform the following configuration in OSPF Area view.

Ta bl e 25 Specifying Interface

Operation Command

Specify an interface to run OSPF network ip-address ip-mask

Disable OSPF on the interface undo network ip-address ip-mask

You must specify the segment to which the OSPF will be applied after enabling the OSPF tasks.

Configuring Router ID

A router ID is a 32-bit unsigned integer that uniquely identifies a router within an AS. A router ID can be configured manually. If a router ID is not configured, the system selects the IP address of an interface automatically. When you set a router ID manually, you must guarantee that the IDs of any two routers in the AS are unique. A common undertaking is to make the router ID the same as the IP address of an interface on the router.

86 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Perform the following configurations in system view.

Ta bl e 26 Configuring Router ID

Operation Command

Configure router ID router id router-id

Remove the router ID undo router id

To ensure the stability of OSPF, you must determine the division of router IDs and manually configure them when implementing network planning.

Configuring the Network Type on the OSPF Interface

The route calculation of OSPF is based on the topology of the adjacent network of the local router. Each router describes the topology of its adjacent network and transmits it to all the other routers.

OSPF divides networks into four types by link layer protocol:

■ Broadcast: If Ethernet or FDDI is adopted, OSFP defaults the network type to

broadcast.

■ Non-Broadcast Multi-access (NBMA): If Frame Relay, ATM, HDLC or X.25 is

adopted, OSPF defaults the network type to NBMA.

■ Point-to-Multipoint (P2MP): OSPF does not default the network type of any link

layer protocol to P2MP. The general undertaking is to change a partially connected NBMA network to P2MP network, if the NBMA network is not fully-meshed.

■ Point-to-point (P2P): If PPP, LAPB or POS is adopted, OSPF defaults the network

type to P2P.

As you configure the network type, consider the following points:

■ NBMA means that a network is non-broadcast and multi-accessible. ATM is a

typical example. You can configure the polling interval for hello packets before the adjacency of neighboring routers is formed.

■ Configure the interface type to nonbroadcast on a broadcast network without

multi-access capability.

■ Configure the interface type to P2MP if not all the routers are directly

accessible on an NBMA network.

■ Change the interface type to P2P if the router has only one peer on the NBMA

network.

The differences between NBMA and P2MP are listed below:

■ In OSPF, NBMA refers to the networks that are fully connected, non-broadcast

and multi-accessible. However, a P2MP network is not required to be fully connected.

■ DR and BDR are required on a NBMA network but not on a P2MP network.

■ NBMA is the default network type. For example, if ATM is adopted as the link

layer protocol, OSPF defaults the network type on the interface to NBMA, regardless of whether the network is fully connected. P2MP is not the default network type. No link layer protocols are regarded as P2MP. You must change

OSPF 87

the network type to P2MP manually. The most common method is to change a partially connected NBMA network to a P2MP network.

■ NBMA forwards packets by unicast and requires neighbors to be configured

manually. P2MP forward packets by multicast.

Perform the following configuration in VLAN interface view.

Ta bl e 27 Configuring a Network Type on the Interface that Starts OSPF

Operation Command

Configure network type on the interface ospf network-type { broadcast | NBMA |

P2MP | P2P }

Restore the default network type of the OSPF interface

undo ospf network-type

After the interface has been configured with a new network type, the original network type is removed automatically.

Configuring the Cost for Sending Packets on an Interface

The user can control the network traffic by configuring different message sending costs for different interfaces. Otherwise, OSPF automatically calculates the cost according to the baud rate on the current interface.

Perform the following configuration in VLAN interface view.

Ta bl e 28 Configuring the Cost for Sending Packets on the Interface

Operation Command

Configure the cost for sending packets on interface

Restore the default cost for packet transmission on the interface

ospf cost value

undo ospf cost

Setting the Interface Priority for DR Election

The priority of the router interface determines the qualification of the interface for DR election. A router of higher priority is considered first if there is a collision in the election.

DR is not designated manually, instead, it is elected by all the routers on the segment. Routers with priorities > 0 in the network are eligible candidates. Among all the routers self-declared to be the DR, the one with the highest priority is elected. If two routers have the same priority, the one with the highest router ID is elected DR. Each router writes the expected DR in the packet and sends it to all the other routers on the segment. If two routers attached to the same segment concurrently declare themselves to be the DR, the one with the higher priority wins. If the priorities are the same, the router with higher router ID wins. If the priority of a router is 0, it is not eligible to be elected DR or BDR.

If a DR fails, the routers on the network must elect a new DR and synchronize with the new DR. The process takes a relatively long time, during which, route calculation can become incorrect. To speed up this DR replacement process, OSPF implements the BDR as a backup for DR. The DR and BDR are elected at the same time. The adjacencies are also established between the BDR and all the routers on the segment, and routing information is exchanged between them. When the DR

88 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

fails, the BDR becomes the DR instantly. Since no re-election is needed and the adjacencies have already been established, the process is very short. But in this case, a new BDR must be elected. Although it also takes a long time, it does not affect the route calculation.

Note that:

■ The DR on the network is not necessarily the router with the highest priority.

Likewise, the BDR is not necessarily the router with the second highest priority. If a new router is added after DR and BDR election, it is impossible for the router to become the DR even if it has the highest priority.

■ The DR is based on the router interface in a certain segment. Maybe a router is

a DR on one interface, but it can be a BDR or DROther on another interface.

■ DR election is only required for broadcast or NBMA interfaces. For the P2P or

P2MP interfaces, DR election is not required.

Perform the following configuration in VLAN interface view.

Ta bl e 29 Setting the Interface Priority for DR Election

Operation Command

Configure the interface with a priority for DR election

Restore the default interface priority undo ospf dr-priority

ospf dr-priority priority_num

By default, the priority of the interface is 1 in the DR election. The value can be set from 0 to 255.

Setting the Peer

For an NBMA network, some special configurations are required. Since an NBMA interface on the network cannot discover the adjacent router through broadcasting the Hello packets, you must manually specify an IP address for the adjacent router of the interface, and whether the adjacent router is eligible for election. This can be done by configuring the peer ip-address command. If dr-priority-number is not specified, the adjacent router will be regarded as ineligible.

Perform the following configuration in OSPF view.

Ta bl e 30 Configuring the Peer

Operation Command

Configure a peer for the NBMA interface. peer ip-address [ dr-priority

dr-priority-number ]

Remove the configured peer for the NBMA interface

undo peer ip-address

By default, the preference for the neighbor of NBMA interface is 1.

Setting the Interval of Hello Packet Transmission

Hello packets are the most frequently sent packets. They are periodically sent to the adjacent router for discovering and maintaining adjacency, and for electing a DR and BDR. The user can set the hello timer.

OSPF 89

According to RFC2328, the consistency of hello intervals between network neighbors should be kept. The hello interval value is in inverse proportion to the route convergence rate and network load.

Perform the following configuration in VLAN interface view.

Ta bl e 31 Setting Hello Timer and Poll Interval

Operation Command

Set the hello interval of the interface ospf timer hello seconds

Restore the default hello interval of the interface

Set the poll interval on the NBMA interface ospf timer poll seconds

Restore the default poll interval undo ospf timer poll

undo ospf timer hello

By default, P2P and broadcast interfaces send Hello packets every 10 seconds, and P2MP and NBMA interfaces send the packets every 30 seconds.

Setting a Dead Timer for the Neighboring Routers

If hello packets are not received from a neighboring router, that router is considered dead. The dead timer of neighboring routers refers to the interval after which a router considers a neighboring router dead. You can set a dead timer for the neighboring routers.

Perform the following configuration in VLAN interface view.

Ta bl e 32 Setting a Dead Timer for the Neighboring Routers

Operation Command

Configure a dead timer for the neighboring routers

Restore the default dead interval of the neighboring routers

ospf timer dead seconds

undo ospf timer dead

By default, the dead interval for the neighboring routers of P2P or broadcast interfaces is 40 seconds and for the neighboring routers of P2MP or NBMA interfaces is 120 seconds.

Both hello and dead timers restore the default values if you modify the network type.

Configuring an Interval Required for Sending LSU Packets

Trans-delay seconds should be added to the aging time of the LSA in an LSU packet. Setting the parameter like this, the time duration that the interface requires for transmitting the packet, is considered.

You can configure the interval for sending LSU messages. More attention should be paid to this item on low speed networks.

90 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

Perform the following configuration in VLAN interface view.

Ta bl e 33 Configuring an Interval for LSU packets

Operation Command

Configure an interval for sending LSU packets ospf trans-delay seconds

Restore the default interval of sending LSU packets

By default, LSU packets are transmitted by seconds.

Setting an Interval for LSA Retransmission Between Neighboring Routers

If a router transmits an LSA to the peer, it requires the acknowledgement packet from the peer. If it does not receive the acknowledgement packet within the retransmission, it retransmits this LSA to the neighbor. You can configure the value of the retransmission interval.

Perform the following configuration in VLAN interface view.

Ta bl e 34 Setting Retransmit Timer

undo ospf trans-delay

Operation Command

Configure the interval of LSA retransmission for the neighboring routers

Restore the default LSA retransmission interval for the neighboring routers

ospf timer retransmit interval

undo ospf timer retransmit

By default, the interval for neighboring routers to retransmit LSAs is five seconds.

The value of the interval should be bigger than the interval in which a packet can be transmitted and returned between two routers.

An LSA retransmission interval that is too small will cause unnecessary retransmission.

Setting a Shortest Path First (SPF) Calculation Interval for OSPF

Whenever the OSPF LSDB changes, the shortest path requires recalculation. Calculating the shortest path after a change consumes enormous resources and affects the operating efficiency of the router. Adjusting the SPF calculation interval, however, can restrain the resource consumption caused by frequent network changes.

Perform the following configuration in OSPF view.

Ta bl e 35 Setting the SPF Calculation Interval

Operation Command

Set the SPF calculation interval spf-schedule-interval seconds

Restore the SPF calculation interval undo spf-schedule-interval seconds

By default, the interval for SPF recalculation is 5 seconds.

OSPF 91

Configuring the OSPF STUB Area

STUB areas are special LSA areas in which the ABRs do not propagate the learned external routes of the AS. In these areas, the routing table sizes of routers and the routing traffic are significantly reduced.

The STUB area is an optional configuration attribute, but not every area conforms to the configuration condition. Generally, STUB areas, located at the AS boundaries, are those non-backbone areas with only one ABR. Even if this area has multiple ABRs, no virtual links are established between these ABRs.

To insure that routes to the destinations outside the AS are still reachable, the ABR in this area generates a default route (0.0.0.0) and advertises it to the non-ABR routers in the area.

Note the following items when you configure a STUB area:

■ The backbone area cannot be configured as a STUB area, and virtual links

cannot pass through the STUB area.

■ If you want to configure an area as a STUB area, all the routers in this area

should be configured with the stub command.

■ No ASBR can exist in a STUB area and the external routes of the AS cannot be

propagated in the STUB area.

Perform the following configuration in OSPF Area view.

Ta bl e 36 Configuring an OSPF STUB Area

Operation Command

Configure an area as the STUB area stub [no-summary]

Remove the configured STUB area undo stub

Set the cost of the default route to the STUB area

Remove the cost of the default route to the STUB area

default-cost value

undo default-cost

By default, the STUB area is not configured, and the cost of the default route to a STUB area is 1.

Configuring NSSA of OSPF

An NSSA is similar to a STUB area. However, NSSA does not allow importing AS-External-LSAs (type-5 LSAs) although it does allow importing NSSA-External-LSAs (type-7 LSAs). ASBRs can be configured to convert type-5 LSAs to type-7 LSAs to allow advertising of type-5 LSAs within the NSSA. Similarly, ABRs can be configured to reconvert the type-7 LSAs to type-5 LSAs as these LSAs leave the NSSA.

For example, in Figure 5, the AS running OSPF includes three areas: Area 1, Area 2 and Area 0. Among them, Area 0 is the backbone area. Also, there are other two ASs running RIP. Area 1 is defined as an NSSA. After RIP routes of Area 1 are propagated to the NSSA ASBR, the NSSA ASBR generates type-7 LSAs which are propagated in Area 1. When the type-7 LSAs reach the NSSA ABR, the NSSA ABR translates it into a type-5 LSA, which is propagated to Area 0 and Area 2. On the other hand, RIP routes of the AS running RIP are translated into type-5 LSAs that

92 CHAPTER 5: IP ROUTING PROTOCOL OPERATION

are propagated in the OSPF AS. However, the type-5 LSAs do not reach Area 1 because Area 1 is an NSSA. NSSAs and STUB areas have the same approach in this aspect.

Similar to a STUB area, the NSSA cannot be configured with virtual links.

Figure 5 NSSA

RIP

Area 2

Perform the following configuration in OSPF Area view.

Ta bl e 37 Configuring NSSA of OSPF

Area 0

NSSA ABR

Area 1 NSSA

NSSA ASBR

RIP

Operation Command

Configure an area to be the NSSA area nssa [ default-route-advertise ] [

Cancel the configured NSSA undo nssa

Configure the default cost value of the route to the NSSA

Restore the default cost value of the route to the NSSA area

no-import-route ] [ no-summary ]

default-cost cost

undo default-cost

All routers connected to the NSSA must use the nssa command to configure the area with the NSSA attribute.

The default-route-advertise parameter is used to generate the default type-7 LSAs. The default type-7 LSA route is generated on the ABR, even though the default route 0.0.0.0 is not in the routing table. On an ASBR, however, the default type-7 LSA route can be generated only if the default route 0.0.0.0 is in the routing table.

Executing the no-import-route command on the ASBR prevents the external routes that OSPF imported through the import-route command from advertising to the NSSA. Generally, if an NSSA router is both ASBR and ABR, this argument is used.

The default-cost command is used on the ABR attached to the NSSA. Using this command, you can configure the default route cost on the ABR to NSSA.

By default, the NSSA is not configured, and the cost of the default route to the NSSA is 1.

Configuring the Route Summarization of OSPF Area

Route summary means that ABR can aggregate information of the routes of the same prefix and advertise only one route to other areas. An area can be configured with multiple aggregate segments allowing OSPF to summarize them.

3Com 3.01.01 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

ABOUT THIS GUIDE

Conventions Ta bl e 1 lists icon conventions that are used throughout this book.

SYSTEM ACCESS

■ Product Overview

Ta bl e 1 Function Features

Configuring the Switch 8800

Setting Terminal Parameters

■ Configuring Through Telnet

Command Line Interface

■ Command Line View

PORT CONFIGURATION

Ethernet Port Overview

■ Configuring Ethernet Ports

Configuring Link Aggregation

Load Sharing Link aggregation may be load balancing aggregation or non-load balancing

Port State In an aggregation group, ports may be in selected or standby state and only the

VLAN CONFIGURATION

■ VLAN Overview

■ Configuring VLANs

■ Common VLAN Configuration Tasks

Ta bl e 2 Adding Ethernet Ports to a VLAN

Configuring GARP/GVRP

Configuring GVRP GARP VLAN Registration Protocol (GVRP) is a GARP application. GVRP is based on

NETWORK PROTOCOL OPERATION

Configuring IP Address

Subnet and Mask IP protocol allocates one IP address for each network interface. Multiple IP

Configuring Address Resolution Protocol (ARP)

Configuring ARP The ARP mapping table can be maintained dynamically or manually. Addresses

DHCP Relay Dynamic Host Configuration Protocol (DHCP) offers dynamic IP address

■ Configuring DHCP Relay

IP Performance IP performance configuration includes:

■ Configuring TCP Attributes

■ Displaying and Debugging IP Performance

IPX Configuration 61

IPX Address Structure IPX and IP use different address structures. An IPX address comprises two parts:

IP ROUTING PROTOCOL OPERATION

IP Routing Protocol Overview

■ Selecting Routes Through the Routing Table

Static Routes 67

■ Configuring Static Routes

■ Configuring RIP

OSPF 81

Troubleshooting RIP The Switch 8800 cannot receive update packets when the physical connection to

■ Calculating OSPF Routes

Configuring OSPF You must first enable OSPF then specify the interface and area ID before