Administrator Guide

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
Timer values configured with the neighbor timers command override the timer values configured with the
timers bgp command.
When two neighbors, configured with different keepalive and holdtime values, negotiate for new values, the
resulting values are as follows:
• the lower of the holdtime values is the new holdtime value, and
• whichever is the lower value; one-third of the new holdtime value, or the configured keepalive value is
the new keepalive value.
neighbor update-source
Enable the software to use Loopback interfaces for TCP connections for BGP sessions.
C9000 Series
Syntax
neighbor {ipv6-address | peer-group-name} update-source loopback interface
To use the closest interface, use the no neighbor {ipv6-address | peer-group-name} update-
source loopback interface 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 disable all routers within the peer group.
loopback interface Enter the keyword loopback followed by a number of the loopback interface. The range
is 0 to 16383.
Defaults Not configured.
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 Loopback interfaces are up constantly and the BGP session may need one interface constantly up to stabilize the
session. The neighbor update-source command is not necessary for directly connected internal BGP
sessions.
460 Border Gateway Protocol