To configure BGP to originate a default route to a specific neighbor, use the neighbor default-originate command. Use the optional if-default-present parameter to originate the default route to a specific neighbor only if the default route exists in the routing table.
By default, a neighbor-specific default has no MED and the Origin is IGP. Attributes may be set using an optional route map. A neighbor configured with the default-originate is placed in a separate update group from the neighbors that are not configured with this command which means the global default-originate command does not affect the neighbors configured with this command. The global default-originate command is overridden by the default-originate setting for a neighbor if enabled. The AS PATH sent in the default route update sent to the neighbor as a result of this command includes only the originator's AS. Giving the optional if-default-present tells to originate the default route to this neighbor only if the default route is present in the routing table. This form of default origination does not install a default route in the Adj RIB Out for the update group of peers so configured (it will not appear in show ip bgp neighbor advertised-routes.
A route map may be configured to set attributes on the default route sent to the neighbor. If the route map includes a match ip-address term, that term is ignored. If the route map includes match community or match as-path terms, the default route is not advertised. If there is no route map with the route map name given, the default route is not advertised.
| Default | No default is originated by default. |
| Format | neighbor ip-address default-originate [if-default-present][route-map map-name] |
| Mode | IPv4 VRF Address Family Config |
| Parameter | Description |
|---|---|
| ip-address | The neighbor's IPv4 address. |
| map-name | (Optional) A route map may be configured to set attributes on the default route advertised to the neighbor. |