Administrator Guide

Usage Information To prevent loops, the neighbor ebgp-multihop command does not install default routes of the multihop
peer. Networks not directly connected are not considered valid for best path selection.
neighbor fall-over
Enable or disable fast fall-over for BGP neighbors.
C9000 Series
Syntax
neighbor {ipv6-address | peer-group-name} fall-over
To disable, use the no neighbor {ipv6-address | peer-group-name} fall-over command.
Parameters
ipv6-address Enter the IPv6 address in the x:x:x:x::x format.
NOTE: The :: notation specifies successive hexadecimal fields of zeros.
peer-group-name Enter the name of the peer group.
Defaults Disabled.
Command Modes ROUTER BGP
Command History
Version Description
9.9(0.0) Introduced on the C9010.
9.2(1.0) Introduced on the Z9500.
8.2.1.0 Introduced on the E-Series ExaScale.
7.4.1.0 Introduced
Usage Information When you enable fall-over, BGP keeps track of IP or IPv6 reachability to the peer remote address and the peer
local address. Whenever either address becomes unreachable (for example, no active route exists in the routing
table for peer IP or IPv6 destination/local address), BGP brings down the session with the peer.
Related
Commands
show ip bgp neighbors – displays information on the BGP neighbors.
neighbor filter-list
Configure a BGP filter based on the AS-PATH attribute.
C9000 Series
Syntax
neighbor {ipv6-address | peer-group-name} filter-list as-path-name {in | out}
To delete a BGP filter, use the no neighbor {ipv6-address | peer-group-name} filter-list
as-path-name {in | out} command.
Parameters
ipv6-address Enter the IPv6 address in the x:x:x:x::x format.
NOTE: The :: notation specifies successive hexadecimal fields of zeros.
peer-group-name Enter the name of the peer group to apply the filter to all routers in the peer group.
as-path-name Enter the name of an established AS-PATH access list. If you do not configure the AS-
PATH access list, the default is permit (to allow routes). The maximum is 16 characters.
in Enter the keyword in to filter inbound BGP routes.
out Enter the keyword out to filter outbound BGP routes.
Defaults Not configured.
Border Gateway Protocol 443