Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 232)

218 Brocade Virtual ADX Switch and Router Guide
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Specifying a maximum AS path length
8
To specify asdot notation before displaying IP BGP4 information, use the as-format command.
Syntax: [no] as-format asplain | asdot | asdot+
The default is asplain and can be restored using the no version of the command, if the CLI is
currently using asdot or asdot+.
To activate asdot+ notation, enter as-format asdot+ in the CLI.
Specifying a maximum AS path length
You can use the maxas-limit in command to configure a router running BGP4 to discard routes that
exceed a specified AS path limit. This limit can be configured globally and for BGP neighbors.
When you configure the maxas-limit in setting, the behavior of the router changes to first check the
length of the AS paths in the UPDATE messages and then to apply the inbound policy. If the AS path
exceeds the configured length, then the router performs the following actions:
• Does not store the route in the RIB and does not forward the NLRIs and attributes contained in
the UPDATE message for that route
• Logs an error
• Processes the withdrawn NLRIs in the same update message
If a route from a peer exceeds the configured Maximum AS path limit, the router also removes the
same route from that peer, if it exists, from its own RIB.
After a maximum AS path length is configured, the maximum AS path limit applies to all new
inbound routes. To update previously stored routes, you must perform an inbound soft reset for all
of the address families activated for that particular BGP neighbor session.
NOTE
If the neighbor soft-reconfiguration feature is enabled, you must perform a hard reset on the router
to impose the maximum length limit.
Virtual ADX(config)# router bgp
Virtual ADX(config-bgp-router)# as-format asdot
Virtual ADX(config)# show ip bgp
Total number of BGP Routes: 1
Status codes: s suppressed, d damped, h history, * valid, > best, i internal, S
stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/24 192.168.1.5 1 100 0 1.24464 100 200 65535
1 0 1 1 1 2 1 3 1 9464 ?
Virtual ADX(config)# router bgp
Virtual ADX(config-bgp-router)# as-format asdot+
Virtual ADX(config)# show ip bgp
Total number of BGP Routes: 1
Status codes: s suppressed, d damped, h history, * valid, > best, i internal, S
stale
Origin codes: i - IGP, e - EGP,? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/24 192.168.1.5 1 100 0 1.24464 0.100 0.200
0 65535 1 0 1 1 1 2 1 3 1 9464