HP (Hewlett-Packard) UX 11i User Manual

HP-UX Routing Services Administrator’s

Guide

HP-UX 11i v2

Edition 1

Manufacturing Part Number: B2355-90777

August 2003

U.S.A.

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About This Document

1. Overview

The mrouted Routing Daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Multicasting Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

DVMRP Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

IP Multicast Addresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Multicast Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

The gated Routing Daemon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Deciding When to Use gated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Routing Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2. Conﬁguring mrouted

How to Conﬁgure mrouted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Conﬁguration Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Starting mrouted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Verifying mrouted Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Displaying mrouted Routing Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Multicast Routing Support Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

The mrinfo Tool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

The map-mbone Tool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

The netstat Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Contents

3. Conﬁguring gated

Conﬁguration Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Conﬁguring gated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Converting the Conﬁguration File from 3.0 to 3.5.9. . . . . . . . . . . . . . . . . . . . . . . . . . 49

Conﬁguring the RIP Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

RIP Protocol Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Conﬁguration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Simple RIP Conﬁguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

A: End System on a LAN with RIP Routers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

B: RIP Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Example of a Large RIP Conﬁguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

A: Cluster Node (or Isolated Node). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

B: Cluster (or Root) Server Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

C: End System on a LAN with RIP Routers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Contents

D: Major Router. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

E: Major Router. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Controlling RIP Trafﬁc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Conﬁguring the OSPF Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Planning Your OSPF Conﬁguration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Enabling OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Deﬁning Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

The networks Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

The interface Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Stub Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Deﬁning Backbones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

AS External Routes (AS Boundary Routers Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Sample OSPF Conﬁguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

A: Internal Router (Non-Stub Area). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

B: Area Border Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

C: Internal Router (Stub Area). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Accessing the OSPF MIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Conﬁguring RDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

RDP Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

RDP Client . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Customizing Routes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Specifying a Default Router. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Installing Static Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Setting Interface States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Specifying Tracing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Specifying Route Preference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Importing and Exporting Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

The import Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

The export Statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Examples of import and export Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Starting gated. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99

Verifying That gated Is Running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Troubleshooting gated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Checking for Syntax Errors in the Conﬁguration File . . . . . . . . . . . . . . . . . . . . . . . 101

Contents

Tracing gated Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

Operational User Interface for gated – gdc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

The gated Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

The ripquery Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

The ospf_monitor Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Problem 1: gated does not act as expected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Problem 2: gated deletes routes from the routing table.. . . . . . . . . . . . . . . . . . . . 106

Problem 3: gated adds routes that appear to be incorrect.. . . . . . . . . . . . . . . . . . 107

Problem 4: gated does not add routes that you think it must. . . . . . . . . . . . . . . . 108

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

Contents

About This Document

This manual describes the various routing daemons supported in the HP-UX 11i v2 operating system.It is one of the ﬁve new manuals documenting the Internet Services suite of products. See “Related Documentation” on page 11 for a list of the other new Internet Services manuals. These manuals replace the manual Installing and Administering Internet Services (B2355-90685), which was shipped with previous releases of the operating system.

This manual assumes that the HP-UX 11i v2 operating system software and the appropriate ﬁles, scripts, and subsets are installed.

Intended Audience

This manual is intended for system and network administrators responsible for managing the Routing Services. Administrators are expected to have knowledge of operating system concepts, commands, and the various routing protocols. It is also helpful to have knowledge of Transmission Control Protocol/Internet Protocol (TCP/IP) networking concepts and network conﬁguration; this manual is not a TCP/IP or a routing tutorial.

HP-UX Release Name and Release Identiﬁer

Each HP-UX 11i release has an associated release name and release identiﬁer. The uname (1) command with the -r option returns the release identiﬁer. Table 1 shows the releases available for HP-UX 11i.

Table 1 HP-UX 11i Releases

Release

Identiﬁer

B.11.11 HP-UX 11i v1 PA-RISC B.11.20 HP-UX 11i v1.5 Intel Itanium Processor Family B.11.22 HP-UX 11i v1.6 Intel Itanium Processor Family B.11.23 HP-UX 11i v2.0 Intel Itanium Processor Family

Release Name

Supported Processor

Architecture

Publishing History

Table 2 provides, for a particular document, the manufacturing part number, the respective operating systems, and the publication date.

Table 2 Publishing History Details

Document

Manufacturing

Part Number

B2355-90110 10.x June 1996 B2355-90147 11.0 October 1997 B2355-90685 11.11

11.20

11.22

B5969-4360 11.22 April 2002

What Is in This Document

HP-UX Routing Services Administrator’s Guide is divided into chapters, each of which contain information about conﬁguring the routing services.

Table 3 describes the content in more detail.

Table 3 Document Organization

Chapter Description

Overview Presents an overview of the Routing

Operating

System

Supported

Services and the various protocols that they support.

Publication

Date

December 2000

Conﬁguring mrouted Describes how to conﬁgure mrouted and

various conﬁguration commands in mrouted.

Conﬁguring gated Describes how to conﬁgure gated on RIP,

OSPF, and RDP protocols. This chapter also describes how to specify tracing options, route preference, and some troubleshooting measures in gated.

1 Overview

A router is a device that has multiple network interfaces and that transfers Internet Protocol (IP) packets from one network or subnet to another within an internetwork. In many IP-related documents, this device is also referred to as a gateway. The term router is used in this

Chapter 1 15

Overview

manual. The router stores all the routing information in the form of a routing table. Routing tables contain the routes to reach a particular network, and also identify the router to which the datagram packet can be passed for this purpose. The routing tables must contain the latest routing information. Routing protocols perform the task of updating the routing tables with the latest routing information.

The primary function of a routing protocol is to exchange routing information with other routers. Routing daemons perform the task of exchanging routing information with otherrouters.The routing daemons supported on the HP-UX 11i v2 operating system are mrouted and gated

3.5.9.

A detailed description of the routing daemons, their conﬁguration and troubleshooting information is provided in this manual.

This chapter contains information about the following topics:

• “The mrouted Routing Daemon” on page 17

• “The gated Routing Daemon” on page 22

Chapter 116

Overview

The mrouted Routing Daemon

mrouted (pronounced “M route D”) is a routing daemon that forwards IP multicast datagrams, within an autonomous network, through routers that support IP multicast addressing. mrouted implements the Distance-Vector Multicast Routing Protocol (DVMRP). The ultimate destination of multicast datagrams are host systems thataremembers of one or more multicast groups.

Multicasting enables a client to establish one-to-many and many-to-many communication with other hosts and is used extensively in networking applications such as audio and video teleconferencing, where multiple hosts need to communicate with each other simultaneously.

NOTE You cannot use System Administration Manager (SAM) to conﬁgure

mrouted.

mrouted routes multicast datagram packets only on certain network

interfaces, such as EISA Ethernet (lan2) and EISA FDDI (from a provider other than HP), and the interface types vary depending on the system platform.

When you install the HP-UX 11i v2 operating system, mrouted is automatically installed on your system.

For more information on mrouted, type man 1m mrouted at the HP-UX prompt.

Multicasting Overview

This section describes the multicast routing protocol implemented in mrouted, and the multicast addresses and groups.

DVMRP Protocol

mrouted implements the Distance-Vector Multicast Routing Protocol (DVMRP). You can use DVMRP, an Interior Gateway Protocol (IGP), to route multicast datagrams within an autonomous network. The primary purpose of DVMRP is to maintain the shortest return paths to the source

Chapter 1 17

Overview

The mrouted Routing Daemon

of the multicast datagrams. You can achieve this by using topological knowledge of the network to implement a multicast forwarding algorithm called Truncated Reverse Path Broadcasting (TRPB).

mrouted structures routing information in the form of a pruned broadcast delivery tree that contains routing information. mrouted structures routing information only to those subnets that have members of the destination multicast group. In other words, each router determines which of its virtual network interfaces are in the shortest path tree. In this way, DVMRP can determine if an IP multicast datagram needs to be forwarded. Without such a feature, the network bandwidth can easily be saturated with the forwarding of unnecessary datagrams.

Because DVMRP routes only multicast datagrams, you must handle routing of unicast or broadcast datagrams using a separate routing process.

To support multicasting across subnets that do not support IP multicasting, DVMRP provides a mechanism called tunnelling. Tunnelling forms a virtual point-to-point link between pairs of mrouted routers by encapsulating the multicast IP datagram within a standard IP unicast datagram using the IP-in-IP protocol (IP protocol number 4). This unicast datagram, containing the multicast datagram, is then routed through the intervening routers and subnets. When the unicast datagram reaches the tunnel destination, which is another mrouted router, the unicast datagram is stripped away and the mrouted daemon forwards the multicast datagram to its destinations.

Figure 1-1 shows a tunnel formed between a pair of mrouted routers.

Figure 1-1 Tunnel Made with mrouted Routers

Multicast

Transmitter

Node

DVMRP Tunnel

Endpoint

Router

Nonmulticast

Tunnel

DVMRP Tunnel

Endpoint

Router

Multicast Recipient

Node

Chapter 118

In this ﬁgure, the mrouted router R1 receives a multicast packet from node M. Because R1 is conﬁgured as one end of a tunnel, R1 encapsulates the IP multicast packet in a standard unicast IP packet addressed to the mrouted router R2. The packet, now treated as a normal IP packet, is sent through the intervening nonmulticast network to R2. R2 receives the packet and removes the outer IP header, thereby restoring the original multicast packet. R2 then forwards the multicast packet through its network interface to node N.

IP Multicast Addresses

An IP Internet address can be either a 32-bit or a 128-bit address. Each host on the Internet is assigned a unique IP address. There are four classes of IP addresses: Class A, Class B, Class C, and Class D. Class D IP addresses are identiﬁed as IP multicast addresses. Class A, Class B, and Class C IP addresses are composed of two parts: a network ID (netid) and a host ID (hostid). Class D IP addresses are structured differently, as shown in Figure 1-2.

Figure 1-2 Class D IP Multicast Address Format

Overview

The mrouted Routing Daemon

0123

1110

The ﬁrst 4 bits (0 through 3) identify the address as a multicast address. Bits 4 through 31 identify the multicast group. Multicast addresses are in the range 224.0.0.0 through 239.255.255.255. Addresses 224.0.0.0 through 224.0.0.255 are reserved, and address 224.0.0.1 is permanently assigned to the all hosts group. The all hosts group is used to reach all the hosts on a local network that participate in IP multicasting. The addresses of other permanent multicast groups are published in RFC 1060 (Assigned Numbers, March 1990).

You can use IP multicast addresses only as destination addresses, and they must never appear in the source address ﬁeld of a datagram. Internet Control Message Protocol (ICMP) error messages are not generated for multicast datagrams.

Because IP Internet addressing is a software manifestation of the underlying physical network, you must map IP addresses to physical addresses that the hardware comprising the network understands.

Chapter 1 19

Multicast Group Address

Overview

The mrouted Routing Daemon

Normally, IP multicast addresses are mapped to 802.3 or Ethernet multicast addresses. The IP multicasting addressing scheme, similar to Ethernet’s scheme, uses the datagram’s destination address to indicate multicast delivery.

When an IP multicast address is mapped to an Ethernet multicast address, the low-order 23 bits of the IP multicast address are placed into the low-order 23 bits of the special Ethernet multicast address. The hexadecimal value of the special Ethernet multicast address is 01-00-5E-00-00-00. The resultant Ethernet address, however, is not unique, because only 23 out of the 28 bits representing the multicast address are used.

Multicast Groups

A multicast group comprises hosts with an intention to join the multicast group by listening to the same IP multicast address. Group membership is dynamic, that is, a host may join or leave a group at any time. A host may be a member of one or more groups simultaneously. Additionally, a host is allowed to send multicast datagrams to a group without being a member of the group.

You can assign multicast addresses to transient groups because the multicast address are often temporary. A typical transient group scenario is when users run an application that dynamically registers to speciﬁc multicast addresses,which are discarded later when all members of the group have left. Some multicast addresses may be assigned to permanent groups that always exist, even when their membership is empty.

Both hosts and mrouted routers that participate in IP multicasting use the Internet Group Management Protocol (IGMP) to communicate multicast group information among themselves. Hosts use IGMP to inform mrouted routers that they are joining a group. mrouted routers use IGMP to pass multicast routing information to other mrouted routers, and to check whether a host is still an active group member.

The underlying TCP/IP stack must support ICMP to participate in IP multicasting. While IGMP deﬁnes a standard for communicating information, it does not deﬁne a standard for how the multicast information is propagated among multicast routers. Consequently, DVMRP enables multicast routers to efﬁciently communicate group membership information among themselves. DVMRP uses IGMP messages to carry routing and group membership information. DVMRP

Chapter 120

Overview

The mrouted Routing Daemon

also deﬁnes IGMP message types that enable hosts to join and leave multicast groups, and that allow multicast routers to query one another for routing information.

Chapter 1 21

Overview

The gated Routing Daemon

gated (pronounced “gate D”) is a routing daemon that updates routing tables in internetwork routers. Developed at Cornell University, gated handles the Routing Information Protocol (RIP), External Gateway Protocol (EGP), Border Gateway Protocol (BGP), Open Shortest Path First (OSPF) routing protocol, and the Router Discovery Protocol (RDP), or any combination of these protocols.

Routing protocols are designed to ﬁnd a path between network nodes. If multiple paths exist for a given protocol, the shorter paths are usually chosen. Each protocol has a cost or a metric that it applies to each path. In most cases, the lower the cost or metric for a given path, the more likely a protocol will choose it.

NOTE You cannot use System Administration Manager (SAM) to conﬁgure

gated.

Upon startup, gated reads the kernel routing table on the local machine. gated maintains a complete routing table in the user space, and keeps the kernel routing table (in the kernel space) synchronized with this table.

In large local networks, multiple paths often exist to other parts of the local network. You can use gated to maintain nearly optimal routing to other parts of the local network, and to recover from link failures.

Advantages

gated offers the following advantages:

• Dynamic routing eliminates the need to reset routes manually. When network failures occur, routes are automatically rerouted.

• Dynamic routing facilitates adding and administering nodes.

• Dynamic routing lowers the cost of operating complex Internet systems.

Chapter 122

Overview

The gated Routing Daemon

• gated translates among several protocols, passing information within or between IP routing domains or autonomous systems. Autonomous system (AS) is used here to refer to a group of connected nodes and routers in the same administrative domain that exchange routing information via a common routing protocol.

• gated provides the system administrator ﬂexibility in setting up and controlling network routing. For example, gated can listen to network trafﬁc at speciﬁed routers, determine available routes, and update local routing tables accordingly.

Deciding When to Use gated

gated is mostly used in large networks, or in small networks connected to larger wide area networks.

You must run gated on routers (gateways) to send the routing information to other routers.gated supports many routing protocols that allow routers to build and maintain dynamic routing tables. However, gated also supports RIP, which runs on end systems (systems with only one network interface) as well as on routers.

NOTE gated also supports RDP as a client. RDP will replace rdpd.

gated is useful in topologies with multiple routers and multiple paths

between parts of the network. gated allows routers to exchange routing information and to change routing information dynamically to reﬂect topology changes and maintain optimal routing paths.

Alternatively, you can conﬁgure IP routes manually with the route (1M) command. For end systems in subnets with only one router (gateway) to the Internet, manually conﬁguring a default route is usually more efﬁcient than running gated. For more details on manually manipulating the routing tables, type man 1M route at the HP-UX prompt.

When connected to wide area networks, you can use gated to inject local routing information into the wide area network’s routing table.

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Routing Protocols

For routing purposes, networks and gateways are logically grouped into autonomous system (AS). Companies and organizations that want to connect to the Internet and form an AS must obtain a unique AS number from the Internet Assigned Numbers Authority (IANA).

An interior gateway protocol distributes routing information within the autonomous system. An exterior gateway protocol distributes general routing information about an autonomous system to other autonomous systems.

Dividing networks into autonomous systems keeps route changes inside the autonomous system from affecting other autonomous systems. When routes change within an autonomous system, the new information need not be propagated outside the autonomous system if it is irrelevant to gateways outside the autonomous system.

gated supports the following interior gateway protocols, as deﬁned in IETF RFCs:

• Routing Information Protocol (RIP) is a common routing protocol used within an autonomous system. A de facto industry standard, it is also used by routed, a service distributed by Berkeley. RIP is not intended for use in wide area network (WAN)applications. There are currently two versions of RIP implementations: Version 1, as deﬁned in RFC 1058, and Version 2, as deﬁned in RFC 1388. gated supports all Version 1 features and most of the features of Version 2. The following Version 2 features are not supported: RIP management information base (MIB) route tag, and route aggregation. gated 3.5.9 supports authentication.

• Open Shortest Path First (OSPF), similar to RIP, is a routing protocol that allows routing information to be distributed between routers in an autonomous system. Each router on the network transmits a packet that describes its local links to all other routers. The distributed database is then built from the collected descriptions. If a link fails, updated information ﬂoods the network, allowing all routers to recalculate their routing tables at the same time. OSPF is more suitable than RIP for routing in complex networks with many routers. gated 3.0 supports most of the features of OSPF Version 2, as described in RFC 1247, except the IP type of service (TOS) routing feature. Equal cost multipath routes are limited to one hop per destination, because the HP-UX kernel supports only one gateway per route.

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• HELLO is designed to work with routers called Fuzzballs. Most installations use RIP or OSPF instead of HELLO. The HELLO protocol is no longer supported on HP-UX. You can use RIP or OSPF instead, because they are internal routing protocols.

NOTE Do not mix RIP and OSPF protocols within a single network, because the

routing information may conﬂict.

Table 1-1 compares the advantages and disadvantages of the RIP and OSPF protocols.

Table 1-1 Comparison of RIP and OSPF Protocols

RIP OSPF

Advantage: RIP is easy to conﬁgure.

Advantage: An end system (a system with only one network interface) can run RIP in passive mode to listen for routing information.

Disadvantage: RIP may be slow to adjust for link failures.

Disadvantage: OSPF is complicated to conﬁgure and requires network design and planning.

Disadvantage: OSPF does not have a passive mode.

Advantage: OSPF is quick to adjust for link failures.

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Table 1-1 Comparison of RIP and OSPF Protocols (Continued)

RIP OSPF

Disadvantage: RIP generates more protocol trafﬁc than OSPF, because it propagates routing information by periodically transmitting the entire routing table to neighbor routers.

Disadvantage: RIP is not appropriate for large networks, because RIP packet size increases as the number of networks increases.

gated supports the following exterior gateway protocols:

• The External Gateway Protocol (EGP) permits a node on the NSFNET backbone to exchange information with other backbone nodes about reaching a destination. You can use EGP to communicate routing information betweenautonomoussystems. The EGP protocol will be obsoleted in a future release of HP-UX. Use BGP instead of the EGP protocol. BGP offers more ﬂexibility and requires less bandwidth than EGP.

Advantage:OSPF generates less protocol trafﬁc than RIP, because (i) Each router transmits information only about its links instead of the whole routing table, and (ii) OSPF allows you to divide an autonomous system into areas, each with a designated router that exchanges inter-area routing information with other routers. Intra-area routing information is isolated to a single area.

Advantage: OSPF works well in large networks.

• The Border Gateway Protocol (BGP) is intended as a replacement for EGP. BGP uses path attributes to select routes. One of the attributes that BGP can pass is the sequence of autonomous systems that must be traversed to reach a destination. gated supports BGP Versions 2, 3, and 4, as described in RFCs 1163 and 1267.

gated also supports the Router Discovery Protocol (RDP), which is neither an interior nor an exterior gateway protocol. RDP is used to inform hosts of the existence of routers to which the hosts can send

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packets. It is used instead of, or in addition to, a statically conﬁgured default router. Router discovery consists of two parts: a server part that runs on routers, and a client part that runs on hosts.

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Chapter 128

2 Conﬁguring mrouted

This chapter describes how to conﬁgure mrouted and the various conﬁguration commands in mrouted. It also provides information on starting and verifying the mrouted installation. A description of the mrouted routing tables is also provided, along with the various multicast

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Conﬁguring mrouted

routing support tools. This chapter discusses the following topics:

• “How to Conﬁgure mrouted” on page 31

• “Starting mrouted” on page 36

• “Verifying mrouted Operation” on page 37

• “Displaying mrouted Routing Tables” on page 38

• “Multicast Routing Support Tools” on page 41

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