Advertise the Default BGP4 Route

A BGP4 default route is the IP address 0.0.0.0 and the route prefix 0 or network mask 0.0.0.0. For example, 0.0.0.0/0 is a default route.

About this task

By default, a BGP4 device does not originate and advertise the default BGP4 route. You can configure a BGP4 device to advertise the default IPv4 route to all BGP4 neighbors and to install that route in the local BGP4 route table.

Before you begin

The default route must be present in the local IPv4 route table.

Procedure

  1. Access global configuration mode.
    device# configure terminal
  2. Access BGP configuration mode.
    device(config)# router bgp
  3. Access IPv4 address family unicast configuration mode.
    device(config-bgp-router)# address-family ipv4 unicast
  4. Configure the device to originate and advertise the default BGP route and to install that route in the local BGP4 route table.
    device(config-bgp-ipv4u)# default-information-originate

Example

This example summarizes the commands in this procedure.

device# configure terminal
device(config)# router bgp
device(config-bgp-router)# address-family ipv4 unicast
device(config-bgp-ipv4u)# default-information-originate