Setup Guide

Match a Clause with a Continue Clause
The continue feature can exist without a match clause.
Without a match clause, the continue clause executes and jumps to the specied route-map entry. With a match clause and a continue
clause, the match clause executes rst and the continue clause next in a specied route map entry. The continue clause launches only after
a successful match. The behavior is:
A successful match with a continue clause—the route map executes the set clauses and then goes to the specied route map entry
after execution of the continue clause.
If the next route map entry contains a continue clause, the route map executes the continue clause if a successful match occurs.
If the next route map entry does not contain a continue clause, the route map evaluates normally. If a match does not occur, the route
map does not continue and falls-through to the next sequence number, if one exists
Set a Clause with a Continue Clause
If the route-map entry contains sets with the continue clause, the set actions operation is performed rst followed by the continue clause
jump to the specied route map entry.
If a set actions operation occurs in the rst route map entry and then the same set action occurs with a dierent value in a subsequent
route map entry, the last set of actions overrides the previous set of actions with the same
set command.
If the set community additive and set as-path prepend commands are congured, the communities and AS numbers are
prepended.
Conguring BGP Confederations
Another way to organize routers within an AS and reduce the mesh for IBGP peers is to congure BGP confederations.
As with route reectors, BGP confederations are recommended only for IBGP peering involving many IBGP peering sessions per router.
Basically, when you congure BGP confederations, you break the AS into smaller sub-AS, and to those outside your network, the
confederations appear as one AS. Within the confederation sub-AS, the IBGP neighbors are fully meshed and the MED, NEXT_HOP, and
LOCAL_PREF attributes are maintained between confederations.
To congure BGP confederations, use the following commands.
Species the confederation ID.
CONFIG-ROUTER-BGP mode
bgp confederation identifier as-number
as-number: from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte).
Species which confederation sub-AS are peers.
CONFIG-ROUTER-BGP mode
bgp confederation peers as-number [... as-number]
as-number: from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte).
All Confederation routers must be either 4 Byte or 2 Byte. You cannot have a mix of router ASN support.
To view the conguration, use the show config command in CONFIGURATION ROUTER BGP mode.
Border Gateway Protocol (BGP)
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