HP (Hewlett-Packard) UX 11i User Manual

Download

HP-UX Routing Services Administrator’s

Guide

HP-UX 11i v2

Edition 1

Manufacturing Part Number: B2355-90777

August 2003

U.S.A.

Legal Notices

The information in this document is subject to change without notice.

Hewlett-Packard makes no warranty of any kind with regard to this manual, including, but not limited to, the implied warranties of merchantability and ﬁtness for a particular purpose. Hewlett-Packard

shall not be held liable for errors contained herein or direct, indirect, special, incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Warranty

A copy of the speciﬁc warranty terms applicable to your Hewlett-Packard product and replacement parts can be obtained from your local Sales and Service Ofﬁce.

U.S. Government License

Proprietary computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license.

Copyright  1997-2003 Hewlett-Packard Development Company L.P. All rights reserved. Reproduction, adaptation, or translation of this document without prior written permission is prohibited, except as allowed under the copyright laws.

This software is based in part on the Fourth Berkeley Software Distribution under license from the Regents of the University of California.

© Copyright 1989-93 The Open Software Foundation, Inc. © Copyright 1986 Digital Equipment Corporation. © Copyright 1990 Motorola, Inc. © Copyright 1990, 1991, 1992 Cornell University © Copyright 1989-1991 The University of Maryland © Copyright 1988 Carnegie Mellon University

Trademark Notices

UNIX is a registered trademark in the United States and other countries, licensed exclusively through The Open Group.

Intel Itanium Processor FamilyisatrademarkofIntelCorporationin the U.S. and other countries and is used under license.

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.

Chapter 1 23

Overview

The gated Routing Daemon

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.

Chapter 124

Overview

The gated Routing Daemon

• 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.

Chapter 1 25

Overview

The gated Routing Daemon

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

Chapter 126

Overview

The gated Routing Daemon

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.

Chapter 1 27

Overview

The gated Routing Daemon

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

Chapter 2 29

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

Chapter 230

Conﬁguring mrouted

How to Conﬁgure mrouted

When the mrouted daemon starts, it automatically reads the default conﬁguration ﬁle /etc/mrouted.conf. You can override the default conﬁguration ﬁle by specifying an alternate ﬁle while invoking mrouted. See “Starting mrouted” on page 36 for more information. If you change the /etc/mrouted.conf ﬁle while mrouted is running, issue the following command to reread the conﬁguration ﬁle:

kill -HUP

By default, mrouted automatically conﬁgures itself to forward on all multicast-capable interfaces, excluding the loopback interface that has the IFF_MULTICAST ﬂag set. Therefore, you do not need to explicitly conﬁgure mrouted, unless you need to conﬁgure tunnel links, change the default operating parameters, or disable multicast routing over a speciﬁc physical interface.

Conﬁguration Commands

You can deﬁne the conﬁguration commands in the /etc/mrouted.conf conﬁguration ﬁle. mrouted supports ﬁve conﬁguration commands: phyint, tunnel, cache_lifetime, pruning, and name. One or more options are associated with each command.

The syntax of each command is as follows:

phyint it

tunnel imit

cache_lifetime c pruning off/on name

local-addr

]

[boundary ( [altnet

local-addr remote-addr

]

[boundary (

boundary-name scoped-addr/mask-len

[disable] [metricm] [thresholdt] [rate_lim

boundary-name|scoped-addr/mask-len

network/mask-len

boundary-name|scoped-addr/mask-len

]

[metricm] [thresholdt] [rate_l

)]

phyint

Chapter 2 31

Conﬁguring mrouted

How to Conﬁgure mrouted

You can use the phyint command to disable multicast routing on the physical interface identiﬁed by the local IP address, Figure 2-1), or to associate a nondefault metric or threshold with the speciﬁed physical interface. Alternatively, you can replace the local IP address, attached to multiple IP subnets, use the altnet option to describe each additional subnet (one altnet option for each subnet).

tunnel

You can use the tunnel command to establish a tunnel link between the local IP address, (see Figure 2-1). Youcan also use this command to associate a nondefault metric or threshold value with the tunnel. You can replace the local IP address, you can replace the remote IP address, but only if the host name has a single IP address associated with it. Before you can use a tunnel, it must be set up in the mrouted conﬁguration ﬁles of both the mrouted routers participating in the tunnel. mrouted 3.8 does not support the srcrt option. (It provided backwardcompatibility with older versions of mrouted that implemented IP multicast datagram encapsulation using IP source routing.)

local-addr

, with the interface name, such as lan0.Ifphyint is

, and the remote IP address,

, with the interface name, such as lan0. Similarly,

remote-addr

, by a host name,

(see

remote-addr

Chapter 232

Conﬁguring mrouted

How to Conﬁgure mrouted

NOTE A phyint command must precede a tunnel command. All the phyint

and tunnel command options must be placed on a single line except for the boundary and altnet options, which can begin on a separate line.

Figure 2-1 Multicast Network Example Conﬁguration

mrouted

Router

mrouted

Router

195.5.6.7 Node

Node

mrouted

Router

193.3.3.3 mrouted

Router

Node

193.3.4.5

Node

195.5.5.5

Nonmulticast

phyint 193.3.3.3

Tunnel 193.3.4.5 195.5.5.5

phyint 195.5.6.7 Tunnel 195.5.5.5 193.3.4.5

Boundary 193.3.3.3/16

The metric is the cost, or overhead, associated with sending a datagram on the given interface or tunnel, and is used primarily to inﬂuence the choice of routes over which the datagram is forwarded; the larger the value, the higher the cost. You must keep metrics as small as possible, because mrouted cannot route along paths with metrics greater than 31. In general, use a metric value of 1 for all links unless you are speciﬁcally attempting to force trafﬁc to take another route. In this case, the metric of the alternate path should be the sum of the metrics on the primary path + 1. The default metric value is 1.

The threshold is the minimum IP time-to-live (TTL) required for a multicast datagram to be forwarded to a given interface or tunnel. It controls the scope of multicast datagrams. If the TTL value in the datagram is less than the threshold value, the datagram is dropped; if the TTL is greater than or equal to the threshold value, the packet is forwarded. The default threshold value is 1.

Chapter 2 33

Conﬁguring mrouted

How to Conﬁgure mrouted

The TTL value of forwarded packets is only compared with the threshold value; it is not decremented by the threshold. An application that initiates the IP multicast datagram sets the TTL, and typically represents the number of subnets, or hops, the datagram has to traverse to reach its destination. Every time a multicast datagram passes through a multicast router, the TTL value is decremented by 1. HP recommends that you use the default threshold value unless you have a speciﬁc reason to set it otherwise.

In general, all interfaces connected to a particular subnet or tunnel should use the same metric and threshold values for that subnet or tunnel.

You can use the rate_limit option to specify a certain bandwidth in Kbits/second which is allocated to multicast trafﬁc. The default value is 500Kbps on tunnels and 0 (unlimited) on physical interfaces.

You can use the boundary option to conﬁgure an interface as an administrative boundary for the speciﬁed

scoped-addr

option in the phyint and tunnel commands. Packets belonging to the scoped address, which is an IP multicast group address, are not forwarded on this interface. 1s in the mask applied (by means of a bitwise logically AND operation) to the scoped address. For example, the statement boundary

239.2.3.3/16 would result in the mask 255.255.0.0 being calculated by means of an AND operation with 239.2.3.3 to isolate the ﬁrst two octets,

239.2, of the scoped address. Therefore, all IP multicast addresses beginning with 239.2 will not be forwarded on the speciﬁed interface.

boundary-name

(scoped address). You can specify more than one boundary

mask-len

indicates the number of leading

The primary use of the boundary option is to allow concurrent use of the same IP multicast addresses on downstream subnets, without interfering with multicast broadcasts using the same IP multicast addresses on subnets that are upstream from the mrouted gateway.

The cache_lifetime value determines the amount of time that a cached multicast route remains in the kernel before timing out. This value is speciﬁed in seconds and must be between 300 (5 minutes) and 86400 (24 hours). The default value is 300.

You can use the pruning off command to explicitly conﬁgure mrouted as a nonpruning router. When pruning is off, IP multicast datagrams are forwarded to leaf subnets of the broadcast routing tree even when

Chapter 234

Conﬁguring mrouted

How to Conﬁgure mrouted

those leaf subnets do not contain members of the multicast destination group. Use only nonpruning mode for testing. The default mode for pruning is on.

You can use the name command to assign a name ( boundary (a task.

mrouted terminates if it has less than two enabled virtual interfaces (VIFs), where a VIF is either a physical multicast-capable interface or a tunnel. It logs a warning message if all the VIFs are tunnels. HP recommends that you replace such conﬁguration settings with more direct tunnels.

scoped-addr/mask-len

pair) to simplify the conﬁguration

boundary-name

) to a

Chapter 2 35

Conﬁguring mrouted

Starting mrouted

You can start mrouted from the HP-UX prompt or from within a shell script by issuing the following command:

/etc/mrouted [-p] [-c

The -p option disables pruning by overriding the pruning on statement within the /etc/mrouted.conf conﬁguration ﬁle. You must use this option for testing purposes only.

The -c option overrides the default conﬁguration ﬁle /etc/mrouted.conf. Use conﬁguration ﬁle.

The -d be in therange 0 to 3. Toknow more about 1M mrouted at the HP-UX prompt.

By default, mrouted always writes warning and error messages to the system log daemon. You can retrieve these messages from the system log ﬁle, syslog.log, located in the /var/adm/syslog directory.

For convenience in sending signals, mrouted writes its pid to the

/var/tmp/mrouted.pid ﬁle upon startup.

debug_level

config_file

option speciﬁes the debug level.

] [-d

debug_level

to specify an alternate

debug_level

]

debug_level

values,type man

can

Chapter 236

Conﬁguring mrouted

Verifying mrouted Operation

You can use one or more of the following methods to verify mrouted operation:

• Retrieve the virtual interface table and the multicast routing table to verify if appropriate virtual interfaces (vifs) are conﬁgured. See “Displaying mrouted Routing Tables” on page 38 for information on retrieving these tables.

• Retrieve the routing cache table to verify if the routing and cache information is appropriate for your conﬁguration of mrouted. See “Displaying mrouted Routing Tables” on page 38 for information on retrieving this table.

• Examine the syslog ﬁle /var/adm/syslog/syslog.log for warning and error messages that indicate the status of mrouted. Upon startup, mrouted logs a startup message in the syslog ﬁle that indicates the mrouted version number, such as mrouted version

3.8.

• Issue the following ps (process status) command to search for the string “mrouted”, using grep, to determine if the mrouted program is running:

ps -ef | grep mrouted

Chapter 2 37

Conﬁguring mrouted

Displaying mrouted Routing Tables

mrouted contains three routing tables: the virtual interface table, the multicast routing table, and the multicast routing cache table.

The virtual interface table displays the following topological information for each virtual interface:

• Physical and tunnel interfaces.

• The number of incoming and outgoing packets at each interface.

• The value of speciﬁc conﬁguration parameters, such as metric and threshold.

An example virtual interface table is as follows:

Vif Local

Address

0 36.2.0.8 subnet: 36.2 1 1 querier

groups: 224.0.2.1

224.0.0.4 pkts in: 3456 pkts out: 2322323

1 36.11.0.1 subnet: 36.11 1 1 querier

groups: 224.0.2.1

224.0.1.0

224.0.0.4 pkts in: 345 pkts out: 3456

Metric Thresh Flags

2 36.2.0.8 tunnel: 36.8.0.77 3 1

Chapter 238

Conﬁguring mrouted

Displaying mrouted Routing Tables

peers: 36.8.0.77 (2.2) boundaries: 239.0.1

239.1.2 pkts in: 34545433

The multicast routing table displays connectivity information for each subnet from which a multicast datagram can originate.

The multicast routing cache table is a duplicate copy of the kernel forwarding cache table. It contains the status information for multicast destination group-origin subnet pairs.

mrouted retrieves these tables by sending an appropriate signal to the mrouted daemon. mrouted responds to the following signals:

HUP Restarts mrouted. The conﬁguration ﬁle is reread each

time this signal is evoked.

INT Terminates mrouted by sending messages to all

neighboring routers. TERM The same as INT. USR1 Deﬁned as signal 16, dumps the internal routing tables

(virtual interface table and multicast routing table) to

/usr/tmp/mrouted.dump. USR2 Deﬁned as signal 17, dumps the multicast routing

cache tables to /usr/tmp/mrouted.cache. QUIT Dumps the internal routing tables (virtual interface

table and multicast routing table) to stderr (only if

mrouted was invoked with a nonzero debug level). You can send signals to mrouted by issuing the HP-UX kill command at

the HP-UX prompt. For example:

kill -USR1

where

pid

is the process ID of the mrouted daemon.

Formore information on the routing tables, type man 1M mrouted at the HP-UX command prompt, and see the EXAMPLE section.

Chapter 2 39

Conﬁguring mrouted

Displaying mrouted Routing Tables

For more information on signals, type man 1M mrouted at the HP-UX command prompt, and see the Signals section.

Chapter 240

Conﬁguring mrouted

Multicast Routing Support Tools

This section describes various multicast routing support tools.

The mrinfo Tool

mrinfo is a multicast routing tool that requests conﬁguration information from mrouted and prints the information to the standard output. By default, mrouted prints conﬁguration information for its local instance. You can override the default request (the local instance of mrouted) by specifying an alternate router IP address or system name.

For more information, type man 1M mrinfo at the HP-UX command prompt.

The map-mbone Tool

map-mbone is a multicast routing tool that requests multicast router connection information from mrouted and prints the connection map information to the standard output. By default (when no alternate router address is speciﬁed), the request message is sent to all the multicast routers on the local network. If map-mbone discovers new neighbor routers from the replies, it sends an identical request to those routers. This process continues till the list of new neighbors is exhausted.

For more information, type man 1M map-mbone at the HP-UX command prompt.

The netstat Tool

You can used netstat to display multicast-related information, including network statistics and multicast routing table contents.

For more information, type man 1M netstat at the HP-UX command prompt.

Chapter 2 41

Conﬁguring mrouted

Multicast Routing Support Tools

Chapter 242

3 Conﬁguring gated

gated handles multiple routing protocols. You can conﬁgure the gated daemon to perform all or any combination of the supported protocols.

Chapter 3 43

Conﬁguring gated

The HP-UX 11i v2 operating system supports gated 3.5.9. This chapter contains information about how to conﬁgure gated on various routing protocols. It also describes how to specify the tracing options and route preference in gated, and discusses certain troubleshooting measures.

This chapter discusses the following topics:

• “Conﬁguration Overview” on page 45

• “Conﬁguring the RIP Protocol” on page 50

• “Conﬁguring the OSPF Protocol” on page 60

• “Conﬁguring RDP” on page 87

• “Customizing Routes” on page 90

• “Specifying Tracing Options” on page 92

• “Specifying Route Preference” on page 94

• “Importing and Exporting Routes” on page 97

• “Starting gated” on page 99

• “Troubleshooting gated” on page 101 For additional information on gated, type man 1M gated.conf at the

HP-UX prompt.

Chapter 344

Conﬁguring gated

Conﬁguration Overview

Upon startup, gated reads the conﬁguration ﬁle to decide how each protocol must be used to manage routing. By default, it uses the conﬁguration ﬁle named/etc/gated.conf. Creating the conﬁguration ﬁle is usually the responsibility of the system administrator.

The conﬁguration ﬁle can include up to eight sections (called classes) of conﬁguration statements. You can deﬁne the statements further with optional clauses. The eight classes of conﬁguration statements are:

• Directives — Directives are statements that are immediately acted

upon by the gated parser.

• Trace — Trace statement controls gated tracing options.

• Options — Options statements deﬁne global gated options.

• Interface — Interface statements deﬁne router interface options.

• Deﬁnition — Deﬁnition statements identify the autonomous system

that the router belongs to and martian addresses (addresses for which routing information must be ignored).

• Protocol — Protocol statements enable or disable gated protocols

and set protocol options.

• Static — Static statements deﬁne static routes or default routers

that are installed in the kernel routing table.

• Control — Control statements deﬁne routes that are imported to the

router from other routing protocols, and paths that the router exports to other routing protocols.

For a description of each conﬁguration class and to determine which statements belong to which class, type man 4 gated.conf at the HP-UX prompt.

With Version 3.5.9 of gated, the two statements previously in the Trace class (tracefile and traceoptions) have been combined into a single traceoptions statement. Therefore, the tracefile statement has been eliminated. Also, some of the global options have been removed, some new global options have been added, and options have been added for some of the protocols. For details about the new syntax, type man 4 gated.conf at the HP-UX prompt.

Chapter 3 45

Conﬁguring gated

Conﬁguration Overview

If you do not want to use any of the gated 3.5.9 features added at HP-UX

10.30, and do not have any tracing conﬁgured in your gated 3.0 /etc/gated.conf conﬁguration ﬁle, you can continue to use your 3.0 conﬁguration ﬁle with gated 3.5.9. If you do have tracing conﬁgured in your gated 3.0 ﬁle, you must run the conv_config conversion tool on the ﬁle so that it follows the 3.5.9 syntax (see “Converting the Conﬁguration File from 3.0 to 3.5.9” on page 48). For more information about the 3.5.9 syntax, type man 4 gated.conf at the HP-UX prompt.

Tocheck your gated 3.0 conﬁguration ﬁle for compatibility with the 3.5.9 syntax, issue the following command at the command prompt:

gated -c [-f

You need to specify -f

config_file_name

]

only if the conﬁguration ﬁle

you are checking is not the default ﬁle. If you are still running gated 2.0, you must manually edit the

/etc/gated.conf ﬁle so that it follows the 3.5.9 syntax. The conversion utility that was previously available to migrate from gated 2.0 to 3.0 is no longer available, and you can only use the conv_config tool when migrating from 3.0 to 3.5.9.

Conﬁguring gated

To conﬁgure gated, complete the following steps:

1. Issue the following command to create the gated conﬁguration ﬁle

/etc/gated.conf:

gdc newconf

If the protocols are not explicitly speciﬁed, gated assumes the following:

rip yes; ospf no;

2. Determine how you want to conﬁgure each routing protocol, then add the appropriate statements for each protocol to the /etc/gated.conf conﬁguration ﬁle.

See the section “Conﬁguring the OSPF Protocol” on page 60 for OSPF routing conﬁguration statements. RIP conﬁguration is described in “Conﬁguring the RIP Protocol” on page 50. For a more detailed description of the conﬁguration statements, type man 4 gated.conf at the HP-UX prompt.

Chapter 346

Conﬁguring gated

Conﬁguration Overview

3. Add statements for any additional conﬁguration information. See “Customizing Routes” on page 90, “Specifying Tracing Options” on page 92, and “Specifying Route Preference” on page 94 for other conﬁguration options.

In particular, you may want to prevent gated from deleting interfaces from the routing table when gated does not receive routing protocol information from that interface. To do this, insert passive interface deﬁnitions in the interfaces statements. For example:

interfaces {

interface all passive ;

};

: :

4. If you normally use default routes, you must conﬁgure a static default route in the gated conﬁguration ﬁle. If the default route is a gateway node, add the following entry to /etc/gated.conf (enter the gateway node’s IP address for

gateway_IP_Address

static {

default gateway

};

gateway_IP_Address

retain ;

The default route may be a local interface, such as in topologies that include a proxy ARP server on the local network. If the default route is a local interface, add the following entry to /etc/gated.conf:

static {

default interface

};

The

local_IP_Address

retain ;

is the local system’s IP address of the interface or network interface name (that is, lan0, lan1, and so on) that acts as the default route. If you use a proxy ARP server, this is the local address of the interface attached to the same network as the proxy ARP server.

See “Customizing Routes” on page 90 and the section covering “Common Problems” on page 104 in the section “Troubleshooting gated” on page 101 for more information.

5. To check for syntax errors in the conﬁguration ﬁle, run gated with the -c or -C option (gated exits after parsing the conﬁguration ﬁle).

Chapter 3 47

Conﬁguring gated

Conﬁguration Overview

NOTE You can also use the command gdc checkconf to parse the

/etc/gated.conf ﬁle for syntax errors. gdc issues a message to indicate the parsing errors. If there are any errors, the error output is saved to a ﬁle for further inspection. For more details, type man 1M gdc at the HP-UX prompt.

6. Set the environment variable GATED to 1 in the ﬁle /etc/rc.config.d/netconf to invoke gated automatically when the system is started.

7. To start gated, reboot your system or run the following gated startup script:

/sbin/init.d/gated start

You can also start gated by executing the following command:

gdc start

The following message appears:

gated started, pid 25579

where 25579 is the process ID (pid) of the gated process.

Examples of gated conﬁguration ﬁles are included in the sections “Conﬁguring the OSPF Protocol” on page 60 and “Conﬁguring the RIP Protocol” on page 50. Additionally, they are also included in the /usr/newconfig/gated/conf directory.

NOTE HP recommends that you specify the IP address in dot notation (for

example, a.b.c.d) for a conﬁguration option such as a router, host, or interface. Host names with multiple IP addresses associated with them produce errors.

Converting the Conﬁguration File from 3.0 to 3.5.9

To convert a gated 3.0 conﬁguration ﬁle to the gated 3.5.9 syntax, complete the following steps:

Chapter 348

Conﬁguring gated

Conﬁguration Overview

1. Retain a copy of the gated 3.0 conﬁguration ﬁle, because you cannot specify the same ﬁle for input and output while running the

conv_config conversion tool. For example, if you are using /etc/gated.conf for 3.0, type the following command:

cp /etc/gated.conf /etc/gated.conf.30

2. Issue the following command at the HP-UX prompt:

conv_config <

input_config_file_name>output_config_file

where input_config_file_name is the name of the gated 3.0 ﬁle you want

to convert. You must specify this name, because the tool does not assume that you are converting the default ﬁle, /etc/gated.conf.

output_config_file is the name of the new conﬁguration ﬁle for gated 3.5.9. You must specify this name, because the tool does not

assume that you are coverting the default ﬁle, /etc/gated.conf. For example, to convert the gated 3.0 conﬁguration ﬁle to gated

3.5.9, issue the following command:

conv_config < /etc/gated.conf.30 > /etc/gated.conf

After running the conversion tool, you can check the new conﬁguration ﬁle for compatibility using the gated -c command. See the Note in the section “Conﬁguration Overview” on page 45 for more information.

Chapter 3 49

Conﬁguring gated

Conﬁguring the RIP Protocol

RIP uses hopcount to determine the shortest path to a destination. Hopcount is the number of routers a packet must pass through to reach its destination. If a path is directly connected, it has the lowest hopcount of 1. If the path passes through a single router,the hopcount increases to

2. Hopcount can increase to a maximum value of 16, which is RIP’s inﬁnity metric, an indication that a network or node cannot be reached.

If gated encounters an unreachable node, it goes into Holddown Mode. Holddown Mode stops a node from propagating routing information until the other nodes that it is communicating with stabilize their routing information.

Hosts with only one LAN interface may use the RIP protocol with gated to passively listen to routing information when multiple routers on the LAN exist. If only one router on the LAN exists (leaving only one path off the local LAN), you can conﬁgure a static route to that router in the /etc/rc.config.d/net ﬁle, or issue the route command manually, instead of running gated.

In certain cases, you may not want the trafﬁc to follow a certain path, because it incurs an unacceptable cost or security risk. In these cases, gated allows you to assign a metric to each interface. This allows you to select or bypass a path, irrespective of its length or speed.

RIP Protocol Statement

The syntax of the RIP protocol statement is as follows:

rip yes|no | on|off [ {

broadcast|nobroadcast ; nocheckzero ; preference defaultmetric query authentication [none|[[simple|md5] interface

];

[interface ...]

preference

metric

interface_list

metric

;

] [metricout

metric

]

password

]] ;

password

Chapter 350

]

Conﬁguring gated

Conﬁguring the RIP Protocol

trustedgateways sourcegateways traceoptions

}];

router_list

traceoptions

;

Curly braces ({}) are part of the syntax for the RIP protocol statement. Square brackets ([]) are not part of the syntax; they are used here to indicate optional parameters.

yes (or on) informs gated to enable the RIP protocol at this node and to process RIP packets coming in from other nodes. no (or off) informs gated to disable the RIP protocol at this node. If gated ﬁnds fewer than two network interfaces, the node listens to RIP information. If gated ﬁnds two or more network interfaces, the node not only listens but also broadcasts or multicasts the RIP information. If you do not specify a RIP statement in your conﬁguration ﬁle, rip on is assumed.

The following describes the various options in the RIP statement:

• broadcast speciﬁes that RIP packets are always generated. If the RIP protocol is enabled and more than one interface is speciﬁed, broadcast is assumed. Specifying broadcast withonlyone interface is useful only when propagating static routes or routes learned from other protocols.

• nobroadcast speciﬁes that RIP packets are sent only to routers listed in the sourcegateways clause. If the RIP protocol is enabled, but only one interface is speciﬁed, nobroadcast is assumed.

• nocheckzero speciﬁes that the RIP protocol must not check whether the reserved ﬁelds in the RIP packets are zero. In RIP Version 1 (as described in RFC 1058), certain reserved ﬁelds must be zero; however, this may vary in RIP implementations.

• preference determines the order of routes from other protocols to the same destination in the routing table. gated allows one route to a destination per protocol for each autonomous system. In case of multiple routes, the route used is determined by the value of preference.

Default: 100 Range: 0 (most preferred) – 255 (least preferred)

• defaultmetric is the default metric used when propagating routes learned from other protocols.

Default: 16

Chapter 3 51

Conﬁguring gated

Conﬁguring the RIP Protocol

Range: 1 – 16

• query authentication [none|[[simple|md5] speciﬁes the authentication, if any, that is required for query packets that do not originate from routers. If authentication consisting of only a password is required, specify simple If the required authentication consists of a key that was created with the MD5 algorithm, specify md5. Default: none.

• interface is speciﬁed as one of the following (in the order of precedence): an IP address (for example, 193.2.1.36), a domain or interface name (for example, lan0 or lan1), a wildcard name (for example, lan*), or all (which refers to all interfaces). You can specify multiple interface statements with different clauses. If you specify a clause more than once, the instance with the most speciﬁc interface reference is used.

• noripin speciﬁes that gated does not process any RIP information received through the speciﬁed interface. Default: ripin.

• noripout speciﬁes that gated does not send any RIP information through the speciﬁed interface. Default: ripout.

• metricin speciﬁes the incoming metric for all routes propagated to this node through the speciﬁed interface.

Default: kernel interface metric plus 1 (the default RIP hopcount)

• metricout speciﬁes the outgoing metric for all routes propagated by this node through the speciﬁed interface.

password

]]

Default: 0

• version 1 speciﬁes that RIP Version 1 packets (as deﬁned in RFC

1058) are sent; RIP Version 2 packets (deﬁned in RFC 1388) are sent only in response to a Version 2 poll packet. version 2 speciﬁes that RIP Version2 packets are sent to the RIP multicast address or to the broadcast addresses. You can specify how the packets are sent with the multicast or broadcast clauses. version 2 multicast implies that you want to send Version 2 packets (containing subnet mask information). version 2 broadcast implies that you want to send Version 2 packets. If you do not specify a version, version 1 is assumed.

Chapter 352

Conﬁguring gated

Conﬁguring the RIP Protocol

• [secondary] authentication [none|[simple|md5] speciﬁes the type of authentication for RIP Version 2 packets (it is ignored for Version 1 packets). secondary indicates that the secondary authentication is deﬁned; otherwise, the primary authentication is deﬁned. If authentication consisting of only a password is required, specify simple

password

authentication consists of a key that was created with the MD5 algorithm, specify md5. Default: none. (If you do not specify the

authentication clause, the default is primary authentication of none and no secondary authentication.

• trustedgateways provides a list of routers that provide valid RIP routing information; routing packets from other routers are ignored.

• sourcegateways speciﬁes routers to which you can send RIP routing packets. If you specify the nobroadcast clause, routing updates are sent only to routers listed in the sourcegateways clause.

• traceoptions enables tracing for the RIP protocol. See “Specifying Tracing Options” on page 92.

is a quoted string of 0 – 16 characters). If the required

Default: all routers on the attached networks.

password

]

(where

Conﬁguration Options

The -e and -a conﬁguration options help increase the RIP convergent time on the HP-UX operating system. You can set these command-line options in the /etc/gated.conf ﬁle under the RIP protocol statement.

The -e option speciﬁes route_expiry_time, whichis the expiration time used by RIP to determine route aging. The minimum value is 1 second, and the maximum value is 180 seconds. The default value is 180 seconds.

Using the -a option, you can specify the route_update_time option. route_update_time is the time in seconds required by the RIP protocol to send RIP updates to other nodes on the network. The minimum value is 1 second, and the maximum value is 30 seconds. The default value is 30 seconds.

Alternatively, you can manually change the value in the /etc/gated.conf ﬁle. You can specify the -e and -a options either on the command line or in the conﬁguration ﬁle. Conﬁguration ﬁle options override the command-line options.

Chapter 3 53

Conﬁguring gated

Conﬁguring the RIP Protocol

Simple RIP Conﬁguration

A simple RIP conﬁguration consists of RIP routers and end nodes that listen to information exchanged by the RIP routers, as shown in Figure 3-1.

Figure 3-1 and the accompanying text describe conﬁguration of a single end system (node A) and a RIP router (node B). The conﬁguration is the same for multiple end systems and RIP routers (only node B’s conﬁguration is shown here). This exampleshows only the syntax needed for a simple conﬁguration. A detailed description of the entire RIP protocol statement is given after this example.

Figure 3-1 Example of Simple RIP Conﬁguration

End Systems

RIP

Routers

A: End System on a LAN with RIP Routers

Set up the conﬁguration ﬁle /etc/gated.conf in the end system A as follows:

rip yes {

interface 121.1.0.10 version 2 multicast; }; static {

default interface 121.1.0.10 preference 255 ; };

121.1.0.10

. . .

Chapter 354

Conﬁguring gated

Conﬁguring the RIP Protocol

With one interface, A can listen to RIP trafﬁc on the network but does not forward routing information. Routers must be multicasting RIP packets on this network for A to learn about them and update its routing table. The ﬁrst syntax statement enables RIP on node A’s interface (121.1.0.10) to multicast routing information. The second statement speciﬁes a static local default route to prevent gated from deleting it.

B: RIP Router

Set up /etc/gated.conf as follows:

rip yes {

interface all version 2 multicast ; };

This enables the RIP protocol to multicast routing information on all interfaces.

Example of a Large RIP Conﬁguration

Figure 3-2 and the accompanying text describe how to conﬁgure gated for the RIP protocol in each node within a networked system.

B,D, and E pass routing information among themselves and update their routes accordingly. C listens to the RIP conversation between B, D, and E, and updates its routes accordingly. If both the routers D and E can provide a path to a network, but the path through router D is shorter, nodes B, C, and E use router D when routing packets to that network. If D goes down, E becomes the new router to that network for the nodes B, C, and E.

Chapter 3 55

Conﬁguring gated

Conﬁguring the RIP Protocol

Figure 3-2 Example of Large RIP Network

D: Major Router

A: Cluster Node

Isolated Node

134.5.0.1

130.15.0.5

130.15.0.0 (network number)

121.1.0.2

130.15.0.6 121.1.0.92

133.4.0.1

132.5.0.1

B: Root Server

121.1.0.0

F: Single Node

136.5.0.1

136.5.0.0 (network number)

(network number)

121.1.0.10

E: Major Router

121.1.0.15

C: Single Node

132.6.0.1

131.5.0.2

A: Cluster Node (or Isolated Node)

You need not run gated at this node, because it is on a LAN with only one router. Set a static default route to the cluster server (B) in the

/etc/rc.config.d/netconf ﬁle as follows:

ROUTE_DESTINATION[0]= "default" ROUTE_GATEWAY[0]= "130.15.0.6" ROUTE_COUNT[0]= "1"

Chapter 356

Conﬁguring gated

Conﬁguring the RIP Protocol

B: Cluster (or Root) Server Node

Run gated to get routing information about the 121.0.0.0 network. Set up /etc/gated.conf as follows:

interfaces {

interface 130.15.0.6 121.1.0.92 passive ; }; rip yes {

interface 130.15.0.6 noripout ;

interface 121.1.0.92 version 2 multicast; }; static {

default gateway 121.1.0.2 preference 255 ; };

In the previous example, setting rip to yes is similar to setting rip to broadcast. Both the arguments inform the node to send out RIP

packets, because the node has at least two interfaces. To reduce trafﬁc on the 130.15.0.0 LAN, use the noripout option on this interface. This prevents RIP from sending packets on the 130.15.0.0 network.

To isolate the 130.15.0.0 LAN, use the following:

export proto rip interface 121.1.0.92 {

proto direct {

130.15.0.0 restrict ;

}; };

To further isolate the LAN from the 121.1.0.0 LAN, do not specify any static routes that specify that you can reach the LAN through B. See “Importing and Exporting Routes” on page 97 for more information.

Always specify the passive option with the interface’s IP address. It informs gated to maintain the routes even if no other nodes on the

121.0.0.0 network are using RIP. Without this clause, gated changes the preference of the route to the interface if it does not receive routing information for that interface. The static default route adds the speciﬁed default to the kernel routing table. Setting the preference to 255 replaces this route whenever another default route is learned from one of the protocols.

C: End System on a LAN with RIP Routers

Set up /etc/gated.conf as follows:

Chapter 3 57

Conﬁguring gated

Conﬁguring the RIP Protocol

rip yes {

}; static {

};

With one interface, C can listen to RIP trafﬁc on the network but does not forward routing information. Routers must be multicasting RIP packets on this network for C to learn about them and to update its routing table.

D: Major Router

Set up /etc/gated.conf as follows:

rip yes {

};

This runs RIP on all attached networks.

E: Major Router

interface 121.1.0.10 version 2 multicast;

default interface 121.1.0.10 preference 255 ;

interface all version 2 multicast ;

Set up the conﬁguration ﬁle /etc/gated.conf as follows:

rip yes {

interface all version 2 multicast; };

Controlling RIP Trafﬁc

This section describes conﬁguration options for RIP routing information sent by gated from the node. Use these options to hide all or part of your network from other networks or to limit network trafﬁc.

The RIP protocol deﬁnition in the /etc/gated.conf ﬁle contains the following two options for limiting RIP routing information exported by gated:

• The noripout clause in the interface deﬁnition informs gated not to

send any RIP information through the listed interfaces.

• The sourcegateways clause informs gated to send RIP information

directly to the speciﬁed routers.

See “RIP Protocol Statement” on page 50 for more information about these clauses.

Chapter 358

Conﬁguring gated

Conﬁguring the RIP Protocol

The options for limiting RIP routing information imported by gated in the RIP protocol deﬁnition in the /etc/gated.conf ﬁle are as follows:

• The noripin clause in the interface deﬁnition informs gated not to

process RIP information received through the listed interfaces.

• The trustedgateways clause informs gated to listen to RIP

information received only from the speciﬁed routers.

See “RIP Protocol Statement” on page 50 for more information about these clauses.

You can also use the gated import and export statements to restrict and control the route information propagated from one routing protocol to another. See “Importing and Exporting Routes” on page 97 for more information.

Chapter 3 59

Conﬁguring gated

Conﬁguring the OSPF Protocol

Open Shortest Path First (OSPF) is a link-state routing protocol that distributes routing information between routers in a single autonomous system (AS). Each OSPF router transmits a packet with a description of its local links to all other OSPF routers. The distributed database is built from the collected descriptions. Using the database information, each router constructs its own routing table of shortest paths from itself to each destination in the AS.

OSPF allows you to organize routers, networks, and subnetworks within an AS into subsets called areas. An area is a grouping of logically contiguous networks and hosts. Instead of maintaining a topological database of the entire AS, routers in an area maintain the topology for only the area in which they reside. Therefore, all routers belonging to an area must be consistent in their conﬁguration of the area. The topology of an area is hidden from systems that are not part of the area. The creation of separate areas can help minimize overall routing trafﬁc in the AS. Figure 3-3 shows an example of three separate areas deﬁned for an AS.

Chapter 360

Figure 3-3 Areas Deﬁned in an Autonomous System

Area 1

Other AS

Conﬁguring gated

Conﬁguring the OSPF Protocol

Area 2 Area 3

Internal routers have all their directly connected networks in the same area. In Figure 3-3, routers A, B, and H are internal routers.

Routers that are connected to multiple areas are called area border routers. In Figure 3-3, routers F and G are area border routers.

Routers that connect one AS to another are called AS boundary

routers. In Figure 3-3, router D is an AS boundary router. Neighbor routers are routers that interface to a common network.

OSPF uses its own Hello subprotocol to determine which routers are neighbors.In Figure 3-3, routers A, B, and C are a set of neighbor routers that interface to network 1, while routers A and F are another set of neighbor routers that interface to network 2.

Legend:

Network

Router

Area

Backbone

NOTE The Hello subprotocol used with OSPF is not the same as the gated

HELLO protocol. The Hello subprotocol is still supported.

Chapter 3 61

Conﬁguring gated

Conﬁguring the OSPF Protocol

Multi-access networks (networks that can be accessed through two or more neighbor routers) must have one of the routers identiﬁed as a designated router.

Designated routers initiate OSPF protocol functions on behalf of the network. In Figure 3-3, you can access network 1 through the neighbor routers A, B, or C; one of these routers is elected to become the designated router for network 1.

The set of routers that exchange OSPF protocol packets between areas in an autonomous system is called the backbone. In Figure 3-3, routers C, D, E, F, G, and I form an AS backbone that allows protocol packets to travel between the three areas.

OSPF routers exchange various types of link state advertisements to build their topological databases. Most link state advertisements are ﬂooded (sent to every router) throughout the attached area. An exception is the link state advertisement sent out by AS boundary routers that describe routes to destinations outside the AS; these advertisements are ﬂooded throughout the AS. Table 3-1 shows the various types of link state advertisements used by the OSPF protocol.

Table 3-1 Types of Link State Advertisements

Type Content Originated

Router link Router’s links to

area

Network link

Summary link

AS external link

AS boundary routers exchange routing information with routers in other autonomous systems. An AS boundary router can be an area border router or an internal router. It can also be a backbone router, but

List of routers attached to network

Routes to destinations outside area but within AS

Routes to destinations outside AS

Internal and area border routers

Designated router

Area border router

AS boundary router

Flooded Throughout

Area

Chapter 362

Conﬁguring gated

Conﬁguring the OSPF Protocol

it is not required that an AS boundary router be a backbone router. An AS boundary router learns about routes other than its attached AS through exchanges with other routing protocols or through conﬁguration information. Each AS boundary router calculates paths to destinations outside of its attached AS. It then advertises these paths to all routers in its AS.

Following are the two levels of routing in an AS:

• Intra-area routing, where the source and destination of a packet

both reside in the same area. Routing is handled by internal routers.

• Inter-area routing, where the source and destination of a packet

reside in different areas. Packets travel through an intra-area route from the source to an area border router, then travel an inter-area route on a backbone path between areas. Finally, they travel another intra-area route to the destination.

Planning Your OSPF Conﬁguration

Followingis a suggested sequence of steps in planning the OSPF routing in your autonomous system:

1. If your AS exchanges routing information with other autonomous systems, you need to obtain a unique AS number from the Internet Assigned Numbers Authority.

2. Partition the AS into areas. You can partition any interconnected networks into lists of address ranges, with each address range represented as an address-mask pair. The area border routers summarize the area content for each address range and distribute the summaries to the backbone. See “The networks Statement” on page 66 for more information on specifying address ranges.

3. Identify the internal routers for each area. An internal router conﬁguration contains only one area deﬁnition.

4. Identify the area border routers and the areas to which they interface. The conﬁguration for each area border router contains multiple area deﬁnitions.

5. For each router, determine the interface type for each area. Router interfaces can be multicast, non-broadcast multi-access (NBMA), or point-to-point. See “The interface Statement” on page 67 for more information on router interfaces.

Chapter 3 63

Conﬁguring gated

Conﬁguring the OSPF Protocol

6. For multi-access networks, identify a designated router. For NBMA networks, several routers can be designated router candidates. Designated routers are speciﬁed in the interface deﬁnitions (see “The interface Statement” on page 67).

7. You must decide if you want to assign a cost to each interface. See “Cost” on page 79 for more information about costs.

8. Designate stub areas. AS external link advertisements are propagated to every router in every area in an AS, except for routers in the conﬁgured stub areas. See “Stub Areas” on page 74 for more information

9. Identify backbone routers. The router conﬁguration contains a backbone deﬁnition and a virtual link deﬁnition, if necessary. See “Deﬁning Backbones” on page 76 for more information

10. Determine if routing packets are authenticated for each area. See “Authentication” on page 77 for more information

11. Identify AS boundary routers. See “AS External Routes (AS Boundary Routers Only)” on page 80 for more information.

Enabling OSPF

The default router identiﬁer used by OSPF is the address of the ﬁrst interface on the router encountered by gated. Toset the router identiﬁer to a speciﬁc address, specify the routerid interface statement in the Deﬁnition class of the /etc/gated.conf ﬁle.

NOTE You must enable the OSPF protocol only for routers. When the OSPF

protocol is enabled for a system, the system is treated as a router, and not a host, by other hosts.

You can enable the OSPF protocol using the ospf statement in the Protocol class of the /etc/gated.conf ﬁle. The clause yes (or on) informs gated to enable the OSPF protocol at this node and to process all OSPF packets arriving from other nodes. If you do not specify an OSPF line in your conﬁguration ﬁle, ospf no is assumed. The clause no (or off) informs gated to disable the OSPF protocol on this node.

The following is an example to enable OSPF:

ospf yes { ... }

Chapter 364

Conﬁguring the OSPF Protocol

The following sections explain other statements deﬁned for the OSPF protocol conﬁguration.

Deﬁning Areas

Each OSPF router is associated with one or more areas. The area statement identiﬁes an OSPF area. The value is in the form of a dotted quad, or a number between 1 and 4294967295. To deﬁne an area, you must specify the following:

• The addresses of the networks that make up the area.

• The router interfaces used to communicate with the area. The conﬁguration of an area border router contains multiple area

deﬁnitions; a different router interface is deﬁned for each area. Figure 3-4 shows an example of an area border router that is connected to area 0.0.0.1 through interface 193.2.1.33 and to area 0.0.0.2 through interface 193.2.1.17.

Figure 3-4 Area Border Router Conﬁguration Example

Conﬁguring gated

Area 0.0.0.1

193.2.1.33

Area

Border

193.2.1.17

to Network Bto Network A

Area 0.0.0.2

Router

The following is an example of the area deﬁnitions in the router’s

/etc/gated.conf ﬁle:

ospf yes {

area 0.0.0.1 {

interface 193.2.1.33 {

...

}; }; area 0.0.0.2 {

interface 193.2.1.17 {

...

};

Chapter 3 65

Conﬁguring gated

Conﬁguring the OSPF Protocol

You can deﬁne various characteristics for an area and interfaces. The following sections describe the conﬁguration statements that you can use in deﬁning an area.

The networks Statement

The networks statement deﬁnes the address ranges that forms an OSPF area. This deﬁnition applies only to area border routers, where multiple areas are speciﬁed, and is required only if you need to compress a number of subnets using a network mask.

A network address followed by a hexadecimal bit mask speciﬁes an IP address range in the network statement. For example, the following address range begins with the network address 193.2.1.16 and includes the ﬁrst 15 addresses in that network (193.2.1.17 through 193.2.1.31):

193.2.1.16 mask 0xfffffff0

You can specify many separate networks in an address range. Area border routers advertise a single route for each address range.

Figure 3-5 shows an example of a router that is connected to area 0.0.0.1 through the interface 193.2.1.33. The attached network consists of addresses 193.2.1.33 through 193.2.1.47. The other network in the area consists of addresses 193.2.1.17 through 193.2.1.31.

Figure 3-5 Network Conﬁguration Example

Area 0.0.0.1

193.2.1.17

193.2.1.18

193.2.1.19

. . .

193.2.1.31

Router B

193.2.1.47

193.2.1.34

193.2.1.35

193.2.1.36

. . .

193.2.1.33

Router A

Chapter 366

Conﬁguring gated

Conﬁguring the OSPF Protocol

The following is an example of the network deﬁnition in the Router A’s

/etc/gated.conf ﬁle:

ospf yes

area 0.0.0.1

networks {

193.2.1.16 mask 0xfffffff0 ;

193.2.1.32 mask 0xfffffff0 ; }; interface 193.2.1.33 {

...

};

...

The interface Statement

The interface statement in the OSPF protocol deﬁnition speciﬁes the interface to use while communicating with the speciﬁed networks. You can specify the interface with an address (for example, 193.2.1.36), a domain or interface name (for example, lan0 or lan1), a wild card name (for example, lan*), or all (the order of precedence is address, name, wild card name, all). You can specify multiple interface statements using different clauses. If you specify a clause more than once, the instance with the most speciﬁc interface reference is used.

You can specify the cost clause optionally to deﬁne a cost of sending a packet on the interface. This cost is advertised as the link cost for this interface. See “Cost” on page 79 for more information on setting interface costs.

You can also enable or disable the interface deﬁnition. If you do not explicitly specify disable, an interface deﬁnition is enabled by default.

OSPF supports the following types of network interfaces:

• A multicast (or broadcast) network is a network that supports two or more attached routers and allows a single message to be addressed to a set of network nodes at the same time. An example of a multicast network is an Ethernet LAN.

• A non-broadcast multi-access (NBMA) network is a network that supports multiple attached routers, but does not support broadcasting of messages. An example of an NBMA network is an X.25 PDN.

Chapter 3 67

Conﬁguring gated

Conﬁguring the OSPF Protocol

• A point-to-point network is a network that joins a single pair of routers. An example of a point-to-point network is a 56-KB serial line.

The following sections describe each type of interface. Multicast Interfaces On multicast networks, an OSPF router

dynamically detects its neighbor routers through the OSPF Hello message. The following statements are deﬁned for a multicast interface:

• retransmitinterval is the number of seconds between retransmission of link states, database descriptions, and link state request packets. This value must exceed the expected round-trip delay between any two routers in the network. A sample value for a LAN is 5 seconds.

Default: None (you must specify a value) Range: Integer between 0 – 65535

• transitdelay is the number of seconds to transmit a Link State Update Packet over this interface. This value must take into account the transmission and propagation delays for the interface. It must be greater than 0. A sample value for a LAN is 1 second.

Default: None (you must specify a value) Range: Integer between 1 – 65535

• priority speciﬁes the priority of the router to be the designated router. You must conﬁgure this value only for interfaces to multi-access networks. This value speciﬁes the priority of the router to be the designated router. When two routers attached to a network attempt to be the designated router, the one with the higher router priority value takes precedence.

Default: None (you must specify a value for multi-access networks) Range: 8-bit unsigned integer between 0 – 255. 0 means that the

router is ineligible to become a designated router on the attached network.

• hellointerval speciﬁes the time interval (in seconds) for the transmission of OSPF Hello packets. Smaller intervals ensure that changes in network topology are detected faster. A sample value for an X.25 network is 30 seconds. A sample value for a LAN is 10 seconds.

Chapter 368

Conﬁguring gated

Conﬁguring the OSPF Protocol

Default: None (you must specify a value) Range: Integer between 0 – 255

NOTE The hellointerval value must be the same for all OSPF routers.

• routerdeadinterval speciﬁes the time interval (in seconds) for which the Hello packets are not received from a router before it is considered down or inactive by its neighbors. This value must be a multiple of the hellointerval value.

Default: None (you must specify a value) Range: 0 – 65535

NOTE The routerdeadinterval value must be the same for all OSPF

routers.

• You can use the password authkey to validate the protocol packets received on the router interface. The value can be 1 to 8 decimal digits separated by periods, a 1-byte to 8-byte hexadecimal string preceded by 0x, or a string of 1 to 8 characters in double quotes.

Default: None Range: Up to 8 bytes

NOTE To set an authkey value, you must set the authtype clause to 1 or

simple for the area. See “Authentication” on page 77 for more

information on using OSPF authentication.

Chapter 3 69

Conﬁguring gated

Conﬁguring the OSPF Protocol

Figure 3-6 shows an example of a router that is connected to a multicast network through the interface 193.2.1.35.

Figure 3-6 Multicast Router Interface Example

Router

193.2.1.35

Network Network

The following is an example of the multicast interface deﬁnition in the router’s /etc/gated.conf ﬁle:

interface 193.2.1.35 cost 5 {

enable ; priority 15 ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

};

Non-Broadcast Multi-Access (NBMA) Interface On NBMA networks, you must supply the conﬁguration information, including the routers that are attached to the network, so that the OSPF’s Hello protocol communicates with neighbor routers. An NBMA interface deﬁnition applies to both X.25 network interfaces and systems that do not support IP multicasting.Youcan deﬁne an NBMA interface using the multicast interface statements, with the following additions:

• You must specify the clause nonbroadcast in the interface statement.

• pollinterval speciﬁes a rate at which hellos are sent when a neighboring router becomes inactive (a router is considered inactive when hellos are not received from the router for the amount of time

Network

Router

Chapter 370

speciﬁed by the routerdeadinterval deﬁnition). The value of pollinterval must be larger than the value of hellointerval. A

sample value for an X.25 network is 2 minutes.

Default: None (you must specify a value) Range: 0 – 255

• routers specify the list of routers attached to the non-broadcast network. Routers are deﬁned by their IP interface addresses. You must deﬁne the routers that are eligible to be designated routers as eligible.

Figure 3-7 shows an example of a router (A) that is connected to an NBMA network through the interface 193.2.1.35. Two other routers are also attached to the network: router B is connected through the interface

193.2.1.33 and C is connected through the interface 193.2.1.46. B and C

are eligible to be designated routers.

Figure 3-7 Non-Broadcast Router Interface Example

Conﬁguring gated

Conﬁguring the OSPF Protocol

Router

Network

Router

193.2.1.33

Network

The following is an example of the non-broadcast interface deﬁnition in router A’s /etc/gated.conf ﬁle:

Chapter 3 71

193.2.1.35

Internet

193.2.1.46

Router

Network

Conﬁguring gated

Conﬁguring the OSPF Protocol

interface 193.2.1.35 nonbroadcast cost 5 {

};

Point-to-Point Interfaces On point-to-point networks, an OSPF router dynamically detects its neighbor router by sending OSPF Hello packets. The following statements are deﬁned for a point-to-point interface:

• retransmitinterval is the time interval (in seconds) between the retransmission of link states, database descriptions, and link state request packets. This value must exceed the expected round-trip delay between any two routers in the network. A sample value for a LAN is 5 seconds.

routers {

193.2.1.33 eligible ;

193.2.1.46 eligible ; }; priority 15 ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ; pollinterval 20 ;

Default: None (you must specify a value) Range: 0 – 65535

• hellointerval speciﬁes the time interval (in seconds) between transmission of OSPF Hello packets. Smaller intervals ensure that changes in network topology are detected faster. A sample value for an X.25 network is 30 seconds. A sample value for a LAN is 10 seconds.

Default: None (you must specify a value) Range: 0 – 255

NOTE The hellointerval value must be the same for all OSPF routers.

Chapter 372

Conﬁguring gated

Conﬁguring the OSPF Protocol

Default: None (you must specify a value) Range: 0 – 65535

NOTE The routerdeadinterval value must be the same for all OSPF

routers.

You can deﬁne a point-to-point interface with or without a nonbroadcast clause. If you specify the nonbroadcast clause, then you must deﬁne the pollinterval statement.

• pollinterval speciﬁes a rate at which hellos are sent when a neighboring router becomes inactive (a router is considered inactive when hellos have not been received from the router for the amount of time speciﬁed by the routerdeadinterval deﬁnition). The value of pollinterval must be larger than the value of hellointerval. A sample value for an X.25 network is 2 minutes.

Default: None (you must specify a value) Range: 0 – 255

If the device at the other end of the point-to-point network is not an OSPF router, you can prevent sending Hello packets to that OSPF router using the stubhosts statement. stubhosts speciﬁes the IP address or domain name of the non-OSPF host. The cost of sending a packet to the host must also be speciﬁed (in most cases, the host has only a single connection to the network, so the cost conﬁgured has no effect on routing).

Chapter 3 73

Conﬁguring gated

Conﬁguring the OSPF Protocol

Figure 3-8 shows an example of a router (A) that is connected to a non-broadcast, point-to-point network through interface 193.2.1.1.

Figure 3-8 Point-to-Point Router Interface Example

Router

193.2.1.1

193.2.1.2

Router

The following is an example of the interface deﬁnition in router A’s

/etc/gated.conf ﬁle:

interface 193.2.1.1 nonbroadcast cost 5 {

hellointerval 30 ; routerdeadinterval 30 ; retransmitinterval 30 ; pollinterval 30 ;

};

If the router A is connected to a multicast, point-to-point network, you must omit the nonbroadcast clause and the pollinterval statement.

Stub Areas

By default, AS external link advertisements (routes to destinations outside the AS) are propagated to every router in every area in the AS. You can conﬁgure certain OSPF areas as stub areas. AS external link advertisements are not ﬂooded through stub areas. This reduces the size of the topology database that must be maintained by internal routers in the stub area and reduces the protocol trafﬁc through the area. For example, if all the inter-area trafﬁc for an area must go through a single router, then it is not necessary for all routers in the area to receive inter-area routing information.

An area border router advertises a default route in the stub area as the summary of all the IP destinations that are reachable outside the AS. Summary link advertisements (routes to destinations outside the area but within the AS) are still sent into the stub area.

The stub statement speciﬁes that the area is a stub area. You can optionally deﬁne a cost clause to specify the cost associated with the default route that is advertised in the stub area.

Chapter 374

Conﬁguring the OSPF Protocol

Figure 3-9 shows an example of an area border router that is connected to area 0.0.0.2 through interface 193.2.1.20. Because all trafﬁc in and out of the area 0.0.0.2 must pass through router A, it is not necessary for the area’s internal routers, such as router B, to receive inter-area routing information.

Figure 3-9 Area Border Router Conﬁguration Example

193.2.1.16 mask 0xfffffff0

Router

193.2.1.20

193.2.1.17

193.2.1.18

193.2.1.19

Conﬁguring gated

Area 0.0.0.2Area 0.0.0.1

Router

The following is an example of the stub area deﬁnition in the router’s

/etc/gated.conf ﬁle:

OSPF yes {

area 0.0.0.2 {

stub cost 5 ; networks {

193.2.1.16 mask 0xfffffff0 ; }; interface 193.2.1.20 nonbroadcast cost 5 {

enable ; routers {

193.2.1.17 eligible ;

}; priority 5 ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ; pollinterval 20 ;

};

Chapter 3 75

Conﬁguring gated

Conﬁguring the OSPF Protocol

Deﬁning Backbones

The OSPF backbone distributes routing information between areas. You can deﬁne backbones with the same statements and clauses as areas. You need not deﬁne the stub statement for a backbone. The backbone statement is used to deﬁne a router as a backbone router. If an OSPF internal or area boarder router is also a backbone router, the backbone statement must follow the area statements in the /etc/gated.conf ﬁle. Whenever you conﬁgure an area border router (a router connected to multiple areas), you must provide the backbone.

Figure 3-10 shows an example of two area border routers that form part of a backbone. Router A has interfaces to both area 0.0.0.1 and area

0.0.0.2, while router B has interfaces to areas 0.0.0.3 and 0.0.0.4. Router A is connected to router B through interface 15.13.115.156.

Figure 3-10 Backbone Conﬁguration Example

Area 0.0.0.1

Router A Router B

Area 0.0.0.2 Area 0.0.0.4

15.13.115.156

The following is an example of the backbone router deﬁnition in router A’s /etc/gated.conf ﬁle:

Area 0.0.0.3

Chapter 376

Conﬁguring gated

Conﬁguring the OSPF Protocol

backbone {

interface 15.13.115.156 {

enable ; transitdelay 20 ; priority 20 ; hellointerval 30 ; routerdeadinterval 120 ; retransmitinterval 60 ; };

};

If the router is directly attached via a point-to-point interface to a host that is not running OSPF, you can prevent sending OSPF Hello packets to the host. Do this by specifying the subhost statement with the host’s address. You can optionally deﬁne the cost.

NOTE Backbones must be directly connected or contiguous. In some gated

implementations, you can conﬁgure a virtual link to join non-contiguous backbone routers. HP-UX systems do not support virtual links.

Authentication

The OSPF protocol allows youto authenticate packets containing routing information. You can conﬁgure the authentication on a per-area basis; You can use different authentication methods in different areas.

gated supports a simple password authentication method. You can also choose to have no authentication. You can use the authtype statement to deﬁne the authentication method used for the area. 0 or none speciﬁes that routing exchanges in the area are not authenticated. 1 or simple speciﬁes that network passwords of up to 64 bits (8 characters) are used to authenticate packets received from routers in the area.

In the simple password authentication method, all routers that interface to a given network use the same password. The password is deﬁned by the authkey statement in the router’s interface deﬁnition. If you do not conﬁgure a router with the same password as other routers in the network, other networks discard the router’s packets. The password is

Chapter 3 77

Conﬁguring gated

Conﬁguring the OSPF Protocol

conﬁgured on a per-interface basis. If a router has interfaces to more than one network, different passwords can be conﬁgured. This is illustrated in Figure 3-11.

Figure 3-11 Simple Password Authentication

LAN 1

LAN 2

authkey "travis"

authkey "pepe"

The following example shows an authtype statement that enables a simple password authentication for the routers in the area and an authkey statement in the interface deﬁnition that deﬁnes a password (travis) to validate protocol packets received by the router:

area 0.0.0.1 {

authtype simple ; networks {

193.2.1.16 mask 0xfffffff0 ;

193.2.1.32 mask 0xfffffff0 ; };

interface 193.2.1.35 nonbroadcast cost 5 {

routers {

193.2.1.33 eligible ;

193.2.1.46 eligible ; }; priority 15 ; enable ; hellointerval 5 ; routerdeadinterval 20 ;

Chapter 378

retransmitinterval 10 ; pollinterval 20 ; authkey " travis " ;

};

Cost

The outbound side of each router interface is associated with a conﬁgurable cost. Lower cost interfaces are more likely to be used in forwarding data trafﬁc. Cost values are assigned at the discretion of the network or system administrator.While the value is arbitrary, it must be a function of throughput or capacity of the interface: the higher the value, the lower the throughput or capacity. Thus,the interfaces with the highest throughput or capacity must be assigned lower cost values than other interfaces. Interfaces from networks to routers have a cost of 0.

Figure 3-12 shows an example network where costs are speciﬁed for each interface.

Figure 3-12 Cost Conﬁguration Example

Conﬁguring gated

Conﬁguring the OSPF Protocol

193.2.1.35 (cost 5)

193.2.1.33 (cost 5)

LAN 1 193.2.1.32

193.2.1.46 (cost 10)

B C

193.2.1.17 (cost 5)

193.2.1.30 (cost 10)

LAN 2 193.2.1.16

193.2.1.20 (cost 5)

Chapter 3 79

Conﬁguring gated

Conﬁguring the OSPF Protocol

In Figure 3-12, there are two possible packet routes between nodes A and D: one route goes through node B and the other route goes through node C. The cost of each route is calculated as follows:

Node A to node B and node B to node D: 5+5 = 10 Node A to node C and node C to node D: 5+10 = 15 The lowest cost OSPF path between nodes A and D is therefore through

node B. However, packets are rerouted through node C if there is a link failure between node B and LAN 2.

You can optionally deﬁne cost in the following places in the /etc/gated.conf ﬁle:

• In a defaults statement in the OSPF protocol conﬁguration, which applies only to AS boundary routers. This cost deﬁnition applies to routes to destinations outside the AS. These routes may have been derived from other routing protocols, such as EGP. See “AS External Routes (AS Boundary Routers Only)” on page 80 for more information.

• In the export statement in the Control class in the /etc/gated.conf ﬁle, which applies only to AS boundary routers. This cost deﬁnition applies to routes that are exported from the AS boundary router to routers in other autonomous systems.

• In the stub area deﬁnition of the OSPF protocol conﬁguration. This cost deﬁnition speciﬁes the cost of the default summary link that is advertised in the area.

• In the stubhosts deﬁnition of the OSPF protocol conﬁguration. This cost deﬁnition speciﬁes the cost of a point-to-point interface between the router and a non-OSPF host.

• In the subhosts deﬁnition of the OSPF protocol conﬁguration. This cost deﬁnition speciﬁes the cost of a point-to-point interface between the backbone router and a non-OSPF host.

AS External Routes (AS Boundary Routers Only)

AS external (ASE) routes are paths to destinations that are outside the

AS. Most ASE routes are routes to speciﬁc destinations. AS boundary routers specify the ASE routes through another routing protocol, such as EGP, or through conﬁgured routes.

Chapter 380

Conﬁguring gated

Conﬁguring the OSPF Protocol

gated supports the use of route information from other autonomous systems that use other routing protocols, such as EGP. AS boundary routers send AS external link advertisements and ﬂood the AS with advertisements (with the exception of conﬁgured stub areas). A single AS external link advertisement is sent for each external route that the AS boundary router has learned about.

Externally deﬁned routing information and OSPF routing information are maintained separately. In addition, you can tag the externally deﬁned routing information, to identify and store the source of the information along with the route information.

Statements in the Control class of the /etc/gated.conf ﬁle control the importing of routes from routing protocols to a gated forwarding table and the exporting of routes from the gated forwarding table. See “Importing and Exporting Routes” on page 97 for more information.

You must specify the defaults statements in the OSPF protocol conﬁguration only for AS boundary routers. These statements specify how external routing information is handled by the OSPF protocol. You can deﬁne the following in the defaults statements:

• preference speciﬁes the preference value given to the ASE routes imported from other autonomous systems. The preference value determines the order of routes to the same destination in the routing table. gated allows one route to a destination per protocol for each AS. In case of multiple routes, the route used is determined by the lowest preference value (see “Specifying Route Preference” on page 94 for more information). If a preference value is not speciﬁed, ASE routes are imported with a preference of 150.

Default: 150 Range: 0 (most preferred) – 255 (least preferred)

• cost speciﬁes the cost associated with an OSPF route that is exported to other AS boundary routers.

Default: 0 Range: 0 – 65535

• tag speciﬁes an OSPF tag placed on all routes exported by gated into OSPF. You can tag each external route by the AS boundary router to identify the source of the routing information. The tag

Chapter 3 81

Conﬁguring gated

Conﬁguring the OSPF Protocol

value can be an unsigned 31-bit number. You can also specify tag as

as_tag

automatically assigned.

• type determines how ASE routes imported into OSPF are treated. Type 1 routes must be routes from internal gateway protocols with external metrics that are directly comparable to OSPF metrics. When OSPF selects a route, OSPF uses the type 1 route’s external metric and adds the OSPF internal cost to the AS border router. Type 2 routes must be routes fromexternalgateway protocols with metrics that are not comparable to OSPF metrics. When OSPF selects a route, OSPF ignores a type 2 route’s metric and uses only the OSPF internal cost to the AS border router.

• exportlimit speciﬁes the rate at which ASE routes are imported into the gated routing table for each exportinterval.

, where

Default: 1

Default: 100 (ASE routes) Range: 0 – 65535

as_tag

is an unsigned 12-bit number that is

• exportinterval speciﬁes the interval (in seconds) between ASE exports into OSPF.

Default: 1 (second) Range: 0 – 2147483647

Chapter 382

Sample OSPF Conﬁguration

Figure 3-13 shows an example of two areas. Area 1 is a non-stub area, while area 2 is conﬁgured as a stub area. Node B is an area border router between the two areas.

Figure 3-13 OSPF Sample Conﬁguration

Area 1 (Non-Stub)

LAN 1 193.2.1.32

193.2.1.33

Conﬁguring gated

Conﬁguring the OSPF Protocol

193.2.1.35

193.2.1.17

Area 2 (Stub)

A: Internal Router (Non-Stub Area)

Set up /etc/gated.conf as follows:

Chapter 3 83

15.13.115.156

LAN 2 193.2.1.16

193.2.1.20

Conﬁguring gated

Conﬁguring the OSPF Protocol

# Router A Configuration (non-stub area) OSPF yes {

area 0.0.0.1 {

interface 193.2.1.35 cost 5 {

};

The conﬁguration for the internal router A is for a multicast interface. For an NBMA interface, you can set the conﬁguration in

/etc/gated.conf as follows:

# Router A Configuration (non-stub area) OSPF yes {

area 0.0.0.1 {

interface 193.2.1.35 nonbroadcast cost 5 {

};

priority 5 ; enable ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

routers {

193.2.1.33 eligible ;

priority 5 ; enable ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ; pollinterval 20 ;

NOTE If you use IP multicasting in an area, every router and all the

intermediate network devices in that area must support IP multicasting.

B: Area Border Router

Set up /etc/gated.conf as follows:

OSPF yes {

defaults {

cost 5 ;

Chapter 384

}; area 0.0.0.1 {

interface 193.2.1.33 cost 5 {

priority 15 ; enable ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

};

area 0.0.0.2 {

interface 193.2.1.17 cost 5 {

priority 15 ; enable ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

};

backbone {

interface 15.13.115.156 cost 5 {

enable ; priority 10 ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

}; }; };

Conﬁguring gated

Conﬁguring the OSPF Protocol

C: Internal Router (Stub Area)

Set up /etc/gated.conf as follows:

OSPF yes {

area 0.0.0.2 {

stub cost 5 ; interface 193.2.1.20 cost 5 {

priority 5 ; enable ; hellointerval 5 ; routerdeadinterval 20 ; retransmitinterval 10 ;

};

}; };

Chapter 3 85

Conﬁguring gated

Conﬁguring the OSPF Protocol

The routing table on node A contains routes to 193.2.1.32 and 193.2.1.16. The routing table on node C in the stub area contains routes only to LAN 1 and a default router.

Accessing the OSPF MIB

HP’s gated also provides ospfagt, an OSPF Simple Management Network Protocol (SNMP) subagent that supports the OSPF MIB (Management Information Base) (see RFC 1253). The ospfagt subagent works with the HP SNMP Agent, snmpdm. If you use an SNMP manager utility to manage your network, such as HP’s OpenView Network Node Manager, you can also use HP’s OSPF SNMP subagent.

To start ospfagt automatically during system bootup, set the environment variable OSPFMIB to 1 in the ﬁle /etc/rc.config.d/netdaemons.

Tomanually start ospfagt, type the following command at the command prompt:

/usr/sbin/ospfagt

gated must be running before ospfagt is started. Both gated and ospfagt must be running to retrieve OSPF MIB objects.

To load the OSPF MIB, select Load/Unload SNMP:MIBS ... from the Options menu of OpenView.

Chapter 386

Conﬁguring gated

Conﬁguring RDP

You can use Router Discovery Protocol (RDP), a standard protocol, to inform hosts of the presence of routers to which they can send packets. You can also use RDP instead of host wiretapping routing protocols (for example, RIP). It is used instead of, or in addition to, having statically conﬁgured default routes in hosts.

RDP consists of two portions: the server portion, which runs on routers, and the client portion, which runs on hosts. gated treats these portions as separate protocols; therefore, you can enable only one of them at a time. These portions are described in detail in the subsequent sections.

For a description of the RDP conﬁguration statements, type man 4 gated.conf at the HP-UX prompt.

RDP Server

The RDP server runs on routers, and announces the routers’ existence to hosts periodically by multicasting or broadcasting a router advertisement. The advertisement is sent over an RDP server enabled physical interface. Each router advertisement contains a list of all addresses on a physical interface and their preference for being used as a default router. You can conﬁgure the length of time (the lifetime) for which addresses must remain on the list.

At ﬁrst, router advertisements occur every few seconds, and then, they start occurring few minutes. You can conﬁgure the minimum and maximum intervals for router advertisements to occur. Also, a host can send a router solicitation, requesting an advertisement. The router responds with a unicast router advertisement unless a multicast or broadcast advertisement is due to occur.

On hosts that support IP multicasting,router advertisements are sent by default to the all-hosts mulicast address 224.0.0.1. You can also conﬁguration RDP to use broadcasting to send router advertisements. This is useful when a particular host does not support IP multicasting, or when one or more hosts on an attached network do not support IP multicasting. If router advertisements are sent to the all-hosts multicast address, or if an interface is conﬁgured for the limited-broadcast address

255.255.255.255, the advertisements contain all the IP addresses

Chapter 3 87

Conﬁguring gated

Conﬁguring RDP

conﬁgured on the physical interface. If advertisements are sent to a net or subnet broadcast, only that network’s or subnet’s address is included in the advertisement.

An example of the routerdiscovery server statement is as follows:

routerdiscovery server yes {

interface lan1 lan2 maxadvinterval 5 ; address 193.2.1.17 193.2.1.33 193.2.1.46 broadcast preference 50 ;

};

In the example, the server is enabled on the physical interfaces lan1 and lan2, and the IP addresses 193.2.1.17, 193.2.1.33, and 193.2.1.46 are

included in all the router advertisements. Also, the addresses have a preference of 50.

RDP Client

The RDP client runs on hosts, listening for router advertisements over the all-hosts multicast address 224.0.0.1 (if it supports IP multicasting) or on the physical interface’s broadcast address (if the host does not support multicasting). When a host starts up or is reconﬁgured, it sends certain router solicitations requesting advertisements. When it sends the solicitations, it sends them to the all-routers multicast address

224.0.0.2 or to the interface’s broadcast address (if multicasting is not supported).

When the RDP client receives a router advertisement, the host installs a default route to each of the addresses listed in the advertisement. If the advertisement has a preference of ineligible (that is, the addresses in the advertisement are not eligible to be the default route for any hosts), or if the addresses are not on an attached physical interface, the route is marked as unusable but is still retained. If the preference is usable, then that route is among the routes considered. The route with the highest preference is used. If more than one route with the same preference is received, the one with the lowest IP address is used. The default routes are not exportable to other protocols.

If an RDP client receives a router advertisement with a zero lifetime (that is, the addresses in the advertisement are no longer valid), the host deletes all the routes with next-hop addresses learned from that router.

Chapter 388

The host also deletes any routes learned from ICMP redirects pointing to the invalid addresses. Also, if a router advertisement is not received before the addresses listed by the host becomes invalid (that is, before its lifetime expires), the routes learned from that router are deleted by the host.

An example of the routerdiscovery client statement is as follows:

routerdiscovery client yes {

preference 50 ; interface lan0 broadcast ;

};

In the example, the client is enabled on physical interface lan0, and the default routes are given a preference of 50.

A simple example of an RDP server and two RDP clients is shown in Figure 3-14.

Figure 3-14 RDP Server and Clients Example

Router

Conﬁguring gated

Conﬁguring RDP

RDP

Server

lan0

Host A

RDP

Client

Host B

RDP

Client

Chapter 3 89

Conﬁguring gated

Customizing Routes

gated maintains the routing table in user space, and synchronizes this table with the kernel routing table. This section describes statements for setting up customized routes in the Static class of the gated conﬁguration ﬁle, /etc/gated.conf. You can use these statements to specify default routers, static routes, passive interfaces, and routing metrics for interfaces.

Specifying a Default Router

A static route provides a speciﬁc destination for network packets. The static route is a network address or a host address through a router. This route is installed in the kernel’s routing table. The following is an example of a static route for the default route:

static {

default gateway 15.13.114.196 retain ; };

The retain qualiﬁer ensures that the entry is not deleted when gated exists.

Installing Static Routes

The static statement speciﬁes a router or an interface in the kernel routing tables. The following is an example of a static route:

static {

193.2.1.32 mask 0xfffffff0 gateway 193.2.1.30 preference 8 retain ; };

If you specify an export statement for the default route, the route is passed on to other routers. If you specify only the static statement and not an export statement, then the default route is not passed on as a route to other routers. This is considered a passive default route, and is used only by the host where this gated is running. The retain clause retains the route in the kernel even after gated shuts down.

Chapter 390

Conﬁguring gated

Customizing Routes

Setting Interface States

gated times out routes that pass through interfaces not receiving any RIP, OSPF, or BGP packets. The passive clause in the interface statement of the Static class prevents gated from changing the preference of a route to the interface if routing information is not received for the interface. HP recommends that you use the passive clause for all interfaces.

Chapter 3 91

Conﬁguring gated

Specifying Tracing Options

Trace options specify the desired level of tracing output from gated. Tracing output provides useful system information for setting up a node on the network. Use trace options to set up a node and to send a certain type of tracing to a log ﬁle. You can specify tracing in the following ways:

• In a protocol statement in the /etc/gated.conf conﬁguration ﬁle.

• In the Trace class of the /etc/gated.conf conﬁguration ﬁle.

• On the command line with the -t option when starting gated. Trace information is appended to the trace ﬁle unless you specify

replace. Command-line options are useful for tracing events in gated before the conﬁguration ﬁle is read.

NOTE In gated 3.5.9, the two Trace class statements (tracefile and

traceoptions) are combined into one traceoptions statement.

Therefore, the tracefile statement is eliminated. For details about the new syntax, type man 4 gated.conf at the HP-UX prompt.

Table 3-2 shows the gated.conf global trace options related to protocols.

Table 3-2 Protocol-Related Global Trace Options for gated Conﬁguration

Files

Option Effect

state Traces the state machine transitions in the

protocols.

normal Traces the normal protocol events (abnormal

protocol events are always traced).

policy Traces the application of protocol and

user-speciﬁed policies to routes that are imported and exported.

task Traces the system interface and processing

associated with this protocol or peer.

Chapter 392

Conﬁguring gated

Specifying Tracing Options

Table 3-2 Protocol-Related Global Trace Options for gated Conﬁguration

Files (Continued)

Option Effect

timer Traces the timer usage by this protocol or peer. route Traces allroutingtable changes for routes installed

by this protocol or peer.

general A combination of normal and route. all Enables all tracing options.

Some of the options speciﬁed in Table 3-2 do not apply to all of the protocols. For more information on options applicable for each protocol and for the different trace options available within the conﬁguration ﬁle, type man 4 gated.conf at the HP-UX prompt. See “Troubleshooting gated” on page 101 for more information on tracing options.

Chapter 3 93

Conﬁguring gated

Specifying Route Preference

gated maintains a routing table that consists of the route information learned from OSPF and from other active routing protocols, such as RIP or EGP. You can also conﬁgure static routes in the /etc/gated.conf ﬁle with one or more static clauses (see “Installing Static Routes” on page 90 for more information).

The gated routing pool can therefore contain multiple routes to a single destination. When multiple routes exist, the route chosen by gated is determined by the following (in order of precedence):

• The preference value associated with the route. The preference

• If multiple routes use the same protocol and have the same

value is a number in the range from 0 (most preferred) to 255 (least preferred). Routes from different sources have different default preference values. Forexample, OSPF routes within a given AS have a preference value of 10. Table 3-3 shows the default preference values of various types of routes.

preference value, the route with the lowest metric or cost is chosen.

• If metric or cost is the same, the router with the lowest IP address is

chosen.

Table 3-3 Default Preference Values of Routes

Route Type Preference /etc/gated.config Conﬁguration

Interface routes

OSPF interand intra-areas

Internal default

ICMP Redirect 30 Can be changed with redirect

SNMP 50 Canbe changed inSNMP statement in

0 Can be changed with interface

statement in Interface class.

10 Cannot be changed.

20 Generated by BGP or EGP when

routing information is learned from a peer.

statement in Protocol class.

Protocol class.

Chapter 394

Specifying Route Preference

Table 3-3 Default Preference Values of Routes (Continued)

Route Type Preference /etc/gated.config Conﬁguration

Static routes 60 Canbe changed in static statement

in Static class.

RIP 100 Can be changed with import

statement in Control class.

Conﬁguring gated

Point-to-point interface

“Down” interface

OSPF ASE 150 Can be changed in defaults

BGP 170 Can be changed with import

EGP 200 Can be changed with import

Kernel remnant

You can deﬁne preference in the /etc/gated.conf ﬁle conﬁguration ﬁle in the following instances:

• In the static route deﬁnition in the Static class. This preference

deﬁnition sets the preference for static routes. (See “Customizing Routes” on page 90 for more information.) If this option is not set, the preference values for static routes is 60.

110 Can be changed with interface

statement in Interface class.

120 Can be changed with interface

statement in Interface class.

statement in OSPF protocol deﬁnition and with import statement in Control class.

statement in Control class.

254 These are the static routes that are

retained in the kernel after gated is stopped. Preference value cannot be conﬁgured.

• In the interface statement options in the Interface class. This

preference deﬁnition sets the preference for routes to this interface. If this option is not set, the preference value is 0. For more information, type man 4 gated.conf at the HP-UX prompt.

Chapter 3 95

Conﬁguring gated

Specifying Route Preference

• In a defaults statement in the OSPF protocol conﬁguration. This

•Inanimport statement in the Control class of the /etc/gated.conf

preference deﬁnition speciﬁes the preference value of ASE routes that are imported into OSPF. See “ASExternal Routes (AS Boundary Routers Only)” on page 80 for more information. ASE routes are imported into OSPF with a default preference of 150.

ﬁle. This preference deﬁnition overrides any preference deﬁned in the defaults section of the OSPF protocol conﬁguration. See “AS External Routes (AS Boundary Routers Only)” on page 80 and “Importing and Exporting Routes” on page 97 for more information.

Chapter 396

Conﬁguring gated

Importing and Exporting Routes

You can propagate routes from one routing protocol to another using the

import and export control statements. Routes are imported into a gated forwarding table and exported out to the routing protocols.

For more information on import and export statements, type man 4 gated.conf at the HP-UX prompt.

The import Statement

import statements restrict or control routes that are imported to the gated forwarding table. When routes are imported to the gated

forwarding table, you can export them to the routing protocols. You can use import statements to perform the following tasks:

• Prevent routes from being imported into the gated forwarding table

by using a restrict clause.

• Assign a preference value to use when comparing a route with other

routes from other protocols. The route with the lowest preference is installed in the gated forwarding table. The individual protocols conﬁgure the default preferences.

The format of the import statement varies depending on the protocol from which you are importing routes.

With OSPF, you can apply import statements only to OSPF ASE routes. All OSPF intra-area and inter-area routes are imported into the gated forwarding table with an assigned preference of 10.

The export Statement

export statements determine the routes that are exported from the gated forwarding table to the routing protocols. Youcan also restrict the

routes that are exported and assign metrics (values used for route selection) to them. These metrics are applied only after the routes are exported.

The format of the export statement varies depending on the original protocol used to build the routes that you are exporting, and the protocol to which you are exporting routes.

Chapter 3 97

Conﬁguring gated

Importing and Exporting Routes

Examples of import and export Statements

The following import statement imports a BGP route for network

195.1.1 to the gated forwarding table with a preference of 15:

import proto bgp as 1 {

};

The following export statement exports to OSPF the ASE route that was imported to the gated forwarding table in the previous example. The route was originally built by BGP and the destination of the route is network 195.1.1.

export proto ospfase type 1 /* Export an ASE route to OSPF */

};

195.1.1 mask 0xffffff00 preference 15;

proto bgp as 1 {/*route came from BGP and AS 1*/

195.1.1 ; /* the route is to network 195.1.1 */

Chapter 398

Conﬁguring gated

Starting gated

To start gated, complete the following steps:

1. Set the environment variable GATED to 1 in the ﬁle /etc/rc.config.d/netconf to start gated automatically upon system startup.

2. Reboot your system, or issue the following command to run the

gated startup script:

/sbin/init.d/gated start

You can also start gated by running the command gdc start. The following message appears to indicate that gated has started:

gated started, pid 29777

where 29777 is the process ID (pid) of the gated process. You can specify the command-line arguments for starting gated with the GATED_ARGS environment variable in the ﬁle /etc/rc.config.d/netconf. Table 3-4 lists the commonly used command-line options for gated.

Table 3-4 Command Line Options for gated

Flag Effect

-t When used alone, -t causes gated to log all error messages and route changes. It turns on the general trace option automatically. When -t is followed by one or more trace options, only those options are turned on. (See “Specifying Tracing Options” on page 92 for more information.) Multiple trace options are separated by commas. The -t ﬂag must immediately precede the other ﬂags.

-C Speciﬁes that the conﬁguration ﬁle will be parsed for syntax errors. gated exits with a status of 1 if there are any errors and 0 (zero) if there are no errors.

-c Speciﬁes that the conﬁguration ﬁle will be parsed for syntax errors. A dump ﬁle /var/tmp/gated_dump is created if there are no errors. Only the trace option general is logged. See “Specifying Tracing Options” on page 92 for a detailed description of all the tracing options.

Chapter 3 99

Conﬁguring gated

Starting gated

Table 3-4 Command Line Options for gated (Continued)

Flag Effect

-n Speciﬁes that gated will not modify the kernel’s routing tables.

For more information about the command-line options, type man 1M gated at the HP-UX prompt.

Verifying That gated Is Running

Issue the following command to determine if gated is running:

/usr/bin/ps -ef | /usr/bin/grep gated

This command reports the process identiﬁcation (PID), current time, and the command invoked (gated). Following is an example output:

daemon 4484 1 0 Feb 18 ? 0:00 gated

You can also check if gated is running by issuing the following command:

gdc running

The following message appears to indicate that gated is running:

gdc is running (pid 1312)

If gated is not running, the following message appears:

gated is not running

Chapter 3100

HP (Hewlett-Packard) UX 11i User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

About This Document

1 Overview

The mrouted Routing Daemon

Multicasting Overview

DVMRP Protocol

IP Multicast Addresses

Multicast Groups

The gated Routing Daemon

Advantages

Deciding When to Use gated

Routing Protocols

Starting mrouted

Verifying mrouted Operation

Displaying mrouted Routing Tables

Multicast Routing Support Tools

The mrinfo Tool

The map-mbone Tool

The netstat Tool

RIP Protocol Statement

A: End System on a LAN with RIP Routers

B: RIP Router

A: Cluster Node (or Isolated Node)

B: Cluster (or Root) Server Node

C: End System on a LAN with RIP Routers

D: Major Router

E: Major Router

Enabling OSPF

The networks Statement

The interface Statement

Stub Areas

Authentication

Cost

AS External Routes (AS Boundary Routers Only)

A: Internal Router (Non-Stub Area)

B: Area Border Router

C: Internal Router (Stub Area)

Accessing the OSPF MIB

RDP Server

RDP Client

Customizing Routes

Specifying a Default Router

Installing Static Routes

Setting Interface States

Specifying Tracing Options

Specifying Route Preference

Importing and Exporting Routes

The import Statement

The export Statement

Examples of import and export Statements

Starting gated

Verifying That gated Is Running