ADTRAN 1000R Series - Manual (Page 1290)

Command Reference Guide BGP Neighbor Configuration Command Set
61200510L1-35E Copyright © 2005 ADTRAN 1290
next-hop-self
Use the next-hop-self command to force the next hop attribute to be changed to this unit’s address when
advertising networks that would not have the next hop changed under normal rules. Normal next hop rules
are described in the Functional Notes section below. Use the no form of this command to cause normal
next hop rules to apply.
Syntax Description
No subcommands.
Default Values
By default, this command is disabled and normal next hop rules apply.
Applicable Platforms
This command applies to the NetVanta 300, 1000R, 2000, 3000, 4000, and 5000 and Total Access 900
Series units.
Command History
Release 9.3 Command was introduced.
Functional Notes
In eBGP, routes are normally advertised with a next hop set to the IP address that the receiving peer has
configured in its neighbor statement for this router. In the eBGP case where the receiving router is in the
same subnet as the current next hop, the current next hop is not changed.
For broadcast multiaccess networks (Ethernet), this provides more efficient routing. For non-broadcast
multiaccess networks (NBMA) such as Frame Relay with a partial mesh using point-to-multipoint circuits,
this rule can cause significant problems. Since the partial mesh is on the same subnet, BGP applies the
rule of not changing the next hop address, rendering invalid routes in certain topologies. This is one case
where this command is necessary to solve a problem.
Usage Examples
The following example enables next-hop-self:
(config)#router bgp-neighbor 192.22.73.101
(config-bgp-neighbor)#next-hop-self