Reference Guide

Command Mode ROUTER-NEIGHBOR
Usage Information This command avoids installation of default multihop peer routes to prevent loops and creates neighbor
relationships between peers. Networks indirectly connected are not valid for best path selection. The no version of
this command removes multihop session.
Example
OS10(conf-router-neighbor)# ebgp-multihop 2
Supported Releases 10.3.0E or later
enforce-rst-as
Enforces the rst AS in the AS path of the route received from an external border gateway protocol (EBGP) peer to be the same as the
congured remote AS.
Syntax
enforce-first-as
Parameters None
Default Enabled
Command Mode ROUTER-BGP
Usage Information To verify statistics of routes rejected, use the show ip bgp neighbors command. If routes are rejected, the
session is reset. In the event of a failure, the existing BGP sessions ap. For updates received from EBGP peers,
BGP ensures that the rst AS of the rst AS segment is always the AS of the peer, otherwise the update drops
and the counter increments. The no version of this command turns o the default.
Example
OS10(conf-router-bgp-1)# enforce-first-as
Supported Releases 10.3.0E or later
fall-over
Enables or disables BGP session fast fall-over for BGP neighbors.
Syntax
fall-over
Parameters None
Default Disabled
Command Mode ROUTER-NEIGHBOR
Usage Information Congure the BGP fast fall-over on a per-neighbor or peer-group basis. When you enable this command on a
template, it simultaneously enables on all peers that inherit the peer group template. When you enable fall-over,
BGP tracks IP reachability to the peer remote address and the peer local address. Whenever either address
becomes unreachable — no active route exists in the routing table for peer IPv6 destinations or local address —
BGP brings down the session with the peer. The no version of this command disables fall-over.
Example
OS10(conf-router-neighbor)# fall-over
Supported Releases 10.3.0E or later
292 Layer 3