enforce-first-as

Enforces the use of the first autonomous system (AS) path for external BGP (eBGP) routes.
Syntax
enforce-first-as
no enforce-first-as
Modes

BGP configuration mode

Usage Guidelines

This command causes the router to discard updates received from eBGP peers that do not list their AS number as the first AS path segment in the AS_PATH attribute of the incoming route.

The no form of the command disables this feature.

Examples

The following example configures the device to enforce the use of the first AS path. 

device# configure terminal
device(config)# router bgp
device(config-bgp-router)# enforce-first-as
Parent topic: Commands D through H