Redistribution

[The_guroo_2]

guys i was looking at one of my router (work) and saw a strange route-map...the router has RIP and ospf running....in redistirbution there is a rouite-map....which says as follow

route-map xxx deny 10

match interface null0

route-map xxx permit 20

why is that can someone explian this roite map is used while redisribution....thanks as usual

[marikakis]

Hello,

"match interface null0" means that any routes that have null0 as next hop interface are to be matched. The corresponding clause (number 10) has a deny, so matching routes will not be redistributed. In short, routes with a next-hop of null0 are not redistributed.

The next clause (number 20) has a permit and no match criteria, so all other routes are matched and redistributed.

In conclusion, with this map all routes are redistributed, except those that have a next-hop of null0.

Routes with a next-hop of null0 can be configured for example via static route configuration (could be also EIGRP summary routes). What kind of (routing protocol) routes are redistributed into which routing protocol? Are you redistributing lets say static into OSPF?

Kind Regards,

M.