Optional RIP Configuration Tasks

This section covers the commands to perform optional configurations tasks in RIP, such as modifying RIP timers, setting the maximum number of paths to load balance across, and controlling RIP update traffic.

Optional RIP Configuration Tasks

RIP Parameters:

• timers basic update invalid holddown flush

• passive-interface interface_name

• neighbor ip-address

• offset-list [access-list-number | name] {in | out} offset [type number]

• distribute-list [1-199] [in | out] [interface]

• distance weight

• maximum-paths <1-6>

© 2002, CiscoSystems, Inc. All rights reserved.

Cisco CCIE Prep v1.0—Module 6-19

The following is a list of some of the common adjustable parameters within RIP.

■ timers basic update invalid holddown flush This allows the user to set the update, invalid, holddown, and flush timers for RIP.

■ passive-interface interfacename This command prevents the sending of routing updates on an interface; however, the router still listens to updates received from that interface.

■ neighbor ip-address This command defines a RIP neighbor to exchange unicast updates with and should be used in conjunction with the passive-interface command.

■ offset-list [access-list-number | name] {in | out} offset [type number] Use this command to increase the value of the routing metrics. Default values for the access-list-number argument are 0-99. The metric offset cannot exceed 16.

■ distribute-list [1-199] [in | out] [interface] Use this command to call a standard or extended access list to filter inbound and/or outbound routing updates.

■ distance weight {ip-address {ip-address mask}} [ip standard list] [ip extended list] Use this command to change the administrative distance of routes received from a neighbor. If the IP address and wildcardmask are omitted, all routes for that protocol will be set to the distance value.

■ maximum-paths <l-6> Use this command to configure the maximum number of equal cost paths to load balance across. The default setting is 4. A setting of 1 disables load balancing.

This section discusses the major troubleshooting commands for RIP.

Troubleshooting

Troubleshooting Commands:

• show ip protocols {summary}

• show ip route

• debug ip rip {events}

© 2002, CiscoSystems, Inc. All rights reserved. Cisc

3 CCIE Prep v1.0—Module 6-20

show ip protocols {summary} Command show ip protocols {summary} Command

This command displays all routing protocols, detailed timer and metric information, as well as routing update information.

R2 0# show ip protocols

Routing Protocol is "rip" ^-Routing Protocol Type

Sending updates every 30 seconds, next due in 29 seconds

Invalid after 180 seconds, hold down 180, flushed after 240 4-Timer information

Outgoing update filter list for all interfaces is ^-Distribute list (if any)

Incoming update filter list for all interfaces is

Default redistribution metric is 2 ^-Default metric

Redistributing: rip, eigrp 2001 ^-Redistribution is on

Default version control: send version 1, receive any version Interface Send Recv Key-chain

Ethernet0/0 1 12 <-RIP Versions running

Routing for Networks: ^-Networks participating in RIP

128.200.0.0 Passive Interface(s):

Ethernet0/1 <-Network listening to RIP

Routing Information Sources:

Gateway Distance Last Update

128.200.1.1 120 00:00:07 <-RIP Neighbors

Distance: (default is 120) ^-Administrative Distance show ip route Command

This command lists the router's current routing table, and the one on which it makes forwarding decisions. It is possible for a route to exist, or be known to the router, but only the routes with the shortest administrative distances are listed. The output from this command lists what routing protocol the route is from; in the case of the example, R for RIP. The numbers in the bracket behind the route is the administrative distance of the route followed by the hop count. The via field explains who the route is from, how long ago an update was received, and by what interface.

R2 0 show ip route

Gateway of last resort is not set

128.200.0.0/16 is variably subnetted, 4 subnets, 2 masks R 128.200.10.0/24 [120/1] via 128.200.1.1, 00:00:17, Ethernet0/0

C 128.200.1.0/24 is directly connected, Ethernet0/0

R 128.200.2.0/24 [120/1] via 128.200.1.1, 00:00:17, Ethernet0/0

C 128.200.3.16/29 is directly connected, Ethernet0/1

In this instance, the route 128.200.10.0/24 has a metric of 120, and is one hop away. The RIP neighbor providing information about the route is 128.200.1.1, and it sent the last update 17 seconds ago. This is also the next-hop for the targeted network in the routing table. R20 received it through its Ethernet 0/0 port. This is the next-hop interface to reach the destination network.

debug ip rip {events} Command

This command shows all the RIP activity occurring in the router and also displays exactly which interfaces are advertising and receiving routes. The RIP version of the update is also displayed, along with the metric of each route in the update.

R21# debug

ip rip

ld02h

RIP

received v1

update from 128.200.

l0.2 on TokenRingl

ld02h

128.200

l0.

0 in 1 hops

ld02h

RIP

sending

vl

update to 255.255.255

.255 via Ethernetl (l28.200.l.l)

ld02h

subnet

l2 8

.200.10.0, metric 1

ld02h

subnet

l28

.200.2.0, metric 1

ld02h

RIP

sending

vl

update to 255.255.255

.255 via TokenRing0 (l28.200.2.l

ld02h

subnet

l2 8

.200.10.0, metric 1

ld02h

subnet

l28

.200.1.0, metric 1

ld02h

RIP

sending

vl

update to 128.200.10.

2 via TokenRingl (l28.200.l0.l)

ld02h

subnet

l28

.200.10.0, metric 1

ld02h

subnet

l28

.200.1.0, metric 1

ld02h

subnet

l28

.200.2.0, metric 1

0 0

Post a comment