Troubleshooting guide

Troubleshooting

Check all of the statements for hits. Statements that have been misconfigured often have no hits. If the

entire list has no hits, then the list might not have been applied to the BGP neighbor (if the list is applied to

a route map, ensure that the map has been applied to the BGP neighbor). Also, verify that the list is

correctly applied to either inbound or outbound data.

Figure 14 on page 80 shows sample output of the

detailed command.

Number of statements

that filter a range of

routes (for example,

contain ge/le

keywords).

NetVanta_4305#show ip prefix-list detail DEFAULT

ip prefix-list DEFAULT:

count: 2, range entries: 1, sequences: 10 - 20, total hit count: 30

seq 10 deny 192.168.2.0/24 (hit count: 5)

seq 20 permit 192.168.0.0/16 ge 24 le 24 (hit count: 25)

Number of

statements in

the list.

Number of times

this statement has

logged a match.

Figure 14. Viewing a Prefix List

The following are useful tips to keep in mind when searching for misconfigurations in a prefix list:

• If a statement does not include a range of prefixes, the

n a route must match the statement exactly in

order to be selected. Make sure that the prefix length is correct.

• Sequence numbers are important. The router stops processi

ng the list after it finds a match. In Figure

14 on page 80, the deny statement must have a lower sequence numbe

r than the permit statement

because the route specified in the deny sta

tement also matches the permit statement.

•The ge and le keywords match pre

fixes equal to length specified, as well as those greater or lesser than

the specified length. That is, the statement permit 0.0.0.0/0 le 17 will allow /17 routes.

Troubleshooting a Route Map

Use the following Enable mode comma

nd to view a route map:

#show route-map [<name>]

Include the name of a route map to display only the route map matching the specified name. Issuing the

command without entering a name will display all route maps configured on the router.