Bug? OSPF route redistribution filtering with distribution list route-map out

[georgiy_b]

Hi guys, 

I have pretty much the same post in Cisco learning network, however I feel like it is not the place to address this problem.

I was labbing route redistribution into OSPF and found some funny stuff.

So I am applying redistribution route filtering out of EIGRP with access or prefix list

(config-router)# distibute-list 10 out eigrp 37

or

(config-router)# distibute-list prefix test_ospf out eigrp 37

and everything goes as it supposed to go: both access and prefix lists are filtering out routes that are being redistributed into OSPF out of EIGRP.

but... when I am trying to apply route map in the distribute list I am getting this error:

R39(config-router)#distribute-list route-map TEST out eigrp 37

% OUT direction is not allowed in case of OSPF

So now I wonder why route map does not work, but access and prefix lists do? Is there some internal logic I do not know/understand yet?

[Francesco Molino]

Hi

If you want to filter redistribution using route-map, you have to configure it under eigrp for example like:
redistribute ospf X route-map OSPF-to-EIGRP

With distribute list and route-map it will be only inbound direction.

[georgiy_b]

Hello Francesco,

The original post has key words 'out of EIGRP' and 'into OSPF' :). Not vice versa.

And the problem is with this particular command

R39(config-router)#distribute-list route-map TEST out eigrp 37

% OUT direction is not allowed in case of OSPF

Thanks for your input anyway.

[Francesco Molino]

It was an example. Let put it another way.

The command you're trying to implement is under router ospf, right?
The LSDB has to be the same withing the area so you can't filter LSA in this way. However, you're allowed to have a distribute-list inbound to filter what will be installed in the rib.
Is that more clear?

[georgiy_b]

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@Francesco Molino wrote:
The LSDB has to be the same withing the area so you can't filter LSA in this way.  

---

I am not trying to do that. Like at all. I am sorry, if you have been misled by something or misunderstood something in my original post. I thought that the problem is pretty much obvious. 

Moreover, I showed examples when filtering works with prefix and access lists. And, for some reason, it does not work with route map.

The reason it should work is that it actually has nothing to do with what you written above. And it is in my very first post.

It has nothing to do with LSDB consistency, since the routing information is being redistributed from another protocol. And only then the redistributed routes will be sent by ASBR to other OSPF routers to sync LSDB.

P.S.: Just in case I would like to clarify this once more. This is not an inbound route-filtering question. 

[Francesco Molino]

Maybe we misunderstood each other.

Just to recap, you're trying to apply a distribute-list out on your ospf config to filter prefixes out of your ospf. Is that right?

If yes, you can't because the OSPF database (LSDB) as to be the same. To solve this as a workaround, would be to do a distribution list inbound on the other end/routing protocol where you don't want these prefixes.

If not, then I agree I didn't get your point.