Redistributing between Multiple Routing Protocols

[fleadavid]

Hi,

I am having trouble getting routes to share between more than 2 routing protocols.
I can redistribute between 1 routing protocol and another, however that route is never understood by a third routing protocol.
For example I have an OSPF router which changes to BGP, however that route never appears in the next router which is OSPF again.
Sorry if this is not a very good explanation, but any help would be greatly appreciated.

 

[bill001g]

Not a easy question and it varies a little from vendors to vendor. Assuming the OSPF are completely separate...or you get a loop. When you redistribute e-bgp route into OSPF the bgp routers are the only ones that appear in the routing table because they have a better administrative distance. You should see the routes in the ospf database as external routes they just will not be in the routing table of the router that did the redistribution.

 

[fleadavid]

Yeah I appreciate it is an awkward question to answer.

OSPF>>>>OSPF/BGP >>>>>> BGP >>>> BGP/OSPF>>>>>>> OSPF

The redistributed OSPF into BGP routes all appear as BGP, however the far right OSPF route which shows as BGP does not show on any router from the left OSPF router onward.
Hopefully this makes sense.

 

[bill001g]

See if the routes are in the OSPF database. Many times the routes will be in the database but not in the routing table because you are missing a route to the nexthop in the router you did the redistribution in. If they are not in the database then you likely have a filter issue or some problem with the redistribution statement. Also the BGP routes must be EBGP routes or you will need to use a special option but it can cause loops if you are not careful