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neighbor default-originate
Enables a BGP router to forward the default route 0.0.0.0 to a BGP neighbor.
Syntax: [no] neighbor {ip-address | peer-group-name} default-originate
ip-address
IP address of a BGP neighbor to which this router sends the default route.
peer-group-name
Name of a BGP peer group to whose members this router sends the default route. (Use the show ip bgp peer-group command to display the names of defined peer groups.)
Description: The network address 0.0.0.0 is used when no other routes are available. By default, you are not allowed to redistribute network 0.0.0.0. The neighbor default-originate command enables the local router to send the default route 0.0.0.0 to a neighbor. The neighbor can then use this route to reach the router if all other routes are not available.
You do not need to explicitly configure network 0.0.0.0 on the router.
When used in conjunction with a route map, the default route 0.0.0.0 is injected if two condition are met:
- The route map includes a match ip address clause
- There is a route that matches the IP access list exactly
Use the neighbor default-originate command to forward the default route 0.0.0.0 to a neighbor.
Use the no neighbor default-originate command to delete the default route.
Factory Default: No default route forwarded to the neighbor.
Command Mode: Router configuration.
Example 1: In the following example, the neighbor default-originate command enables the router to advertise the default route 0.0.0.0 to neighbor 10.5.1.121, and the show ip bgp neighbor command displays the setting:
router(config)#router bgp 110
router(config-router)#network 10.5.0.0
router(config-router)#neighbor 10.5.1.190 remote-as 120
router(config-router)#neighbor 10.5.1.190 default-originate
router(config-router)#end
router#show ip bgp neighbor 10.5.1.190
BGP neighbor 10.5.1.190 using remote AS 110
router ID: 0.0.0.0 version: 4
state: Connect time: 0:00:00
def orignat: True ebgp multihop: False
Example 2: In the following example
- The access-list command creates an access list named ISP3_Net120 that permits only routes to 120.12.3.0.
- The route-map command creates a route-map named DEFAULT that permits routes that match the IP addresses in access list ISP3_Net120.
- The neighbor remote-as command configures an external neighbor 10.5.1.190.
- The neighbor default-originate command applies the route map DEFAULT to route updates to and from neighbor 10.5.1.121. The router injects the default route to neighbor 10.5.1.121 only if there is a route to 120.12.3.0:
router(config)#access-list ISP3_Net120 permit 120.12.3.0
router(config)#route-map DEFAULT 10 permit
router(config-route-map)#match ip address ISP3_Net120
router(config)#router bgp 110
router(config-router)#network 10.5.0.0
router(config-router)#neighbor 10.5.1.190 remote-as 120
router(config-router)#neighbor 10.5.1.190 default-originate route-map DEFAULT
Related Commands: router bgp
show ip bgp
access-list
route-map
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Copyright © 2004
Avici Systems Inc.
Avici® and TSR®
is a registered trademark of Avici Systems Inc.
IPriori™, Composite Links™, SSR™, QSR, and NSR® are
trademarks of Avici Systems Inc.
Source
File Name: BGP_Nd.fm
HTML File Name: BGP_Nd26.html
Last Updated: 05/10/04 at 16:36:55