Edge-Core AS5700-54X, Cli Reference Manual, Page: 933 / 1116

Chapter 29
| IP Routing Commands
Border Gateway Protocol (BGPv4)
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bgp confederation
identifier
This command configures the identifier for a confederation containing smaller
multiple internal autonomous systems, and declares this router as a member of the
confederation. Use the
no form to remove the confederation identifier.
Syntax
bgp confederation identifier as-number
no bgp confederation identifier
as-number – Autonomous system number which identifies this router as a
member of the specified domain, and tags routing messages passed to
other BGP routers with this number. (Range: 1-4294967295)
Command Mode
Router Configuration
Default Setting
No confederation identifier is configured.
Command Usage
◆
BGP confederations are used to reduce the requirement for fully meshed
connections between iBGP peers in the same AS. It works by dividing up a large
AS into several smaller ASes, where only the peers in the same smaller AS are
fully meshed, thus reducing the number of required connections and routing
traffic.
◆
Even though different local confederation peers may have external BGP (eBGP)
sessions, they exchange routing information among themselves as if they were
iBGP peers. Next hop, Multi Exit Discriminator (MED), and local preference
information is preserved. By preserving this information, a single Interior
Gateway Protocol (IGP) can be used among the local confederations. When
viewed from the outside by external peers, the larger AS is still identified as a
single entity or autonomous system.
◆
Use the bgp confederation peer command to specify the autonomous systems
within a confederation.
Example
Console(config-router)#bgp confederation identifier 600
Console(config-router)#
Related Commands
bgp confederation peer (934)