User Manual

BGP Configuration Examples
228 Enterasys X-Pedition User Reference Manual
BGP Load-Sharing Configuration
The BGP load-sharing feature is used to connect one External BGP peer (protocol 4 only) using up
to four gateways that are statically configured as a gateway list. All prefixes learned from this peer
will be installed into the RIB with this active gateway list. The BGP peering session uses all the
gateways, so the session will be maintained as long as at least one gateway is reachable. All traffic
using these routes will be distributed across the active gateways. Should an interface go down, the
remaining links will assume the load by instantiating new flows across the links. When an interface
comes back up, the gateway list will update to make use of the available link.
Configuration of BGP4 load-sharing requires three entries into the system configuration:
1. A list of gateways that will be used to connect to the peer. These gateways will also be used by
traffic for the routes learned from that peer.
2. A BGP configuration that uses the local loopback IP address as the next-hop gateway to the
configured EBGP peer.
3. A BGP configuration that uses the local loopback IP address as the BGP identifier in our
peering session
Note: BGP v2 and v3 do not support load-sharing.
ip add route <peer-address> gate-list "204.1.1.1 205.1.1.1" retain
bgp set peer-host <peer-address> group <group-name> gateway <local loopback address>
bgp set peer-host <peer-address> group <group-name> local-address <local loopback address>