Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

OSPF route propegation

I am relativley new to OSPF and I have a question regarding Route propegation. If I have the following entry:

router ospf 1

redistribute connected subnets

redistribute static subnets

passive-interface FastEthernet1

network area

network area

Is the mask an exact match on the ip address allowing propegation of only that specific ip address? Also, if I wanted to specify the network for route distribution, what would be the correct wildcard (mask) for use in this scenario?

Thanks in advance,


New Member

Re: OSPF route propegation


network area

defines that any interface matching the above address ( means "this address") will participate in your ospf process number 1, belonging to area

Once that´s running, your router will exchange route information (description of each known interface, including by Link State Advertisements.

Finally, every router will run SPF algorithm and create/update its own routing table.

Route redistribution is a completely separate chapter. First you have to know thar the redistribution command into ospf configuration will take routes from an external source (another process, routing protocol, or static routes). One way to control routing information learnt via redistribution is by using route maps. You could aldo use distribute lists.

In your config, you are using redist connected command. That inserts all your router interfaces into OSPF as External Type 5 routes. You could also use network x.x.x.x area instead, and your connected x.x.x.x interfaces will be announced as local (Type 1) interfaces.

Never forget the SUBNETS keyword for ospf redistribution.

Check for route-map and distribute-list commands for more information.

I hope this helps.



New Member

Re: OSPF route propegation

So all of this routers interfaces and their coresponding subnets are being distributed as external type 5 routes via the "redist connected command"?

What is the advantage of External type5 routes vs local(type1) interfaces?

Thanks again,


CreatePlease to create content