Administrator Guide

Usage Information If you enter bgp dampening, the default values for half-life, reuse, suppress, and max-suppress-
time are applied. The parameters are position-dependent; therefore, if you configure one parameter, you must
configure the parameters in the order they appear in the command.
Related
Commands
show ip bgp dampened-paths – views the BGP paths.
bgp default local-preference
Change the default local preference value for routes exchanged between internal BGP peers.
C9000 Series
Syntax
bgp default local-preference value
To return to the default value, use the no bgp default local-preference command.
Parameters
value Enter a number to assign to routes as the degree of preference for those routes. When
routes are compared, the higher the degree of preference or local preference value, the
more the route is preferred. The range is 0 to 4294967295. The default is 100.
Defaults 100
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 The bgp default local-preference command setting is applied by all routers within the AS.
bgp enforce-first-as
Disable (or enable) enforce-first-as check for updates received from EBGP peers.
C9000 Series
Syntax
bgp enforce-first-as
To turn off the default, use the no bgp enforce-first-as command.
Defaults Enabled.
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
This is enabled by default, that is for all updates received from EBGP peers, BGP ensures that the first AS of the
first AS segment is always the AS of the peer. If not, the update is dropped and a counter is incremented. Use the
show ip bgp neighbors command to view the “failed enforce-first-as check” counter.
If you disable enforce-first-as, you can view it using the show ip protocols command.
Border Gateway Protocol 421