Foundry Configuration Guide for the FESX, FSX, and FWSX
21 - 36 © Foundry Networks, Inc. December 2005
• Configure the local AS number. The local AS number indicates membership in a sub-AS. All BGP routers
with the same local AS number are members of the same sub-AS. BGP routers use the local AS number
when communicating with other BGP routers within the confederation.
• Configure the confederation ID. The confederation ID is the AS number by which BGP routers outside the
confederation know the confederation. Thus, a BGP router outside the confederation is not aware and does
not care that your BGP routers are in multiple sub-ASs. BGP routers use the confederation ID when
communicating with routers outside the confederation. The confederation ID must be different from the sub-
AS numbers.
• Configure the list of the sub-AS numbers that are members of the confederation. All the routers within the
same sub-AS use IBGP to exchange router information. Routers in different sub-ASs within the confederation
use EBGP to exchange router information.
To configure four Layer 3 Switches to be a member of confederation 10 (as shown in Figure 21.3), consisting of
two sub-ASs (64512 and 64513), enter commands such as the following.
Commands for Router A
FESX424 RouterA(config)# router bgp
FESX424 RouterA(config-bgp-router)# local-as 64512
FESX424 RouterA(config-bgp-router)# confederation identifier 10
FESX424 RouterA(config-bgp-router)# confederation peers 64512 64513
FESX424 RouterA(config-bgp-router)# write memory
Syntax: local-as <num>
The <num> parameter with the local-as command indicates the AS number for the BGP routers within the sub-
AS. You can specify a number from 1 – 65535. Foundry recommends that you use a number within the range of
well-known private ASs, 64512 – 65535.
Syntax: confederation identifier <num>
The <num> parameter with the confederation identifier command indicates the confederation number. The
confederation ID is the AS number by which BGP routers outside the confederation know the confederation. Thus,
a BGP router outside the confederation is not aware and does not care that your BGP routers are in multiple sub-
ASs. BGP routers use the confederation ID when communicating with routers outside the confederation. The
confederation ID must be different from the sub-AS numbers. You can specify a number from 1 – 65535.
Syntax: confederation peers <num> [<num> …]
The <num> parameter with the confederation peers command indicates the sub-AS numbers for the sub-ASs in
the confederation. You must specify all the sub-ASs contained in the confederation. All the routers within the
same sub-AS use IBGP to exchange router information. Routers in different sub-ASs within the confederation use
EBGP to exchange router information. You can specify a number from 1 – 65535.
Commands for Router B
FESX424 RouterB(config)# router bgp
FESX424 RouterB(config-bgp-router)# local-as 64512
FESX424 RouterB(config-bgp-router)# confederation identifier 10
FESX424 RouterB(config-bgp-router)# confederation peers 64512 64513
FESX424 RouterB(config-bgp-router)# write memory
Commands for Router C
FESX424 RouterC(config)# router bgp
FESX424 RouterC(config-bgp-router)# local-as 64513
FESX424 RouterC(config-bgp-router)# confederation identifier 10
FESX424 RouterC(config-bgp-router)# confederation peers 64512 64513
FESX424 RouterC(config-bgp-router)# write memory
Commands for Router D
FESX424 RouterD(config)# router bgp
FESX424 RouterD(config-bgp-router)# local-as 64513
FESX424 RouterD(config-bgp-router)# confederation identifier 10
FESX424 RouterD(config-bgp-router)# confederation peers 64512 64513
To Next Page
Loading...
Need help?
General
