I have 10.51.17.0/24 on a ospf router.

[admin@xxxxx] > /ip ad pr
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE

1 10.51.17.1/24 10.51.17.0 bridge1

4 D 10.51.17.1/32 10.51.17.42 <pppoe-xxxr>
5 D 10.51.17.1/32 10.51.17.43 <pppoe-xxx>
6 D 10.51.17.1/32 10.51.17.41 <pppoe-xxxxx>
[admin@xxxxx] > /routing filter export
# jul/30/2014 09:56:13 by RouterOS 6.15
# software id = 8IPL-J1CX
#
/routing filter
add action=discard chain=ospf-out prefix=10.51.17.0/24 prefix-length=24
[admin@xxxx] >

Am I doing something wrong? I am discarding it. But it always redistributes to the other routers.

Dallas

Depends on how those routes are distributed. Routing filters will filter only external routes.

As you see below. I have pppoe routes. This router is in a specific area called area15. Its a stub area. So the backbone isnt directly connected. I am injecting the LSAs to this area. So I get the default route. I dont want every pppoe session distrubuted to the backbone. I want only the 10.51.17.0/24 route distributed. I used /rout ospf area range to summerize. But it dont work here because its not directly connected to the backbone. Is there a way I can use routing filters to stop propergation of non summerized routes /32?

[admin@xxxxx] > /ip ad pr
Flags: X - disabled, I - invalid, D - dynamic
# ADDRESS NETWORK INTERFACE

1 10.51.17.1/24 10.51.17.0 bridge1

4 D 10.51.17.1/32 10.51.17.42 <pppoe-xxxr>
5 D 10.51.17.1/32 10.51.17.43 <pppoe-xxx>
6 D 10.51.17.1/32 10.51.17.41 <pppoe-xxxxx>

I went to the core router. I see the lsa.

backbone summary-n... 10.51.17.0 10.255.255.154 0x80000005 309
backbone summary-n... 10.51.17.41 10.255.255.154 0x80000005 309
backbone summary-n... 10.51.17.42 10.255.255.154 0x80000005 309
backbone summary-n... 10.51.17.43 10.255.255.154 0x80000005 309

I went to 10.255.255.154 which is the ABR of area15 that is connected to the backbone. I installed these on that ABR.

/routing filter
add action=discard chain=ospf-out prefix=10.51.17.41 prefix-length=32
add action=discard chain=ospf-in prefix=10.51.17.41 prefix-length=32

On the core router. The routes are the same. I also tried blocking the whole /24.

Any ideas?

Depends on how those routes are distributed. Routing filters will filter only external routes.

When you say external routes. Do you mean routes that dont originate from the same router the filters are on? Or you do mean when I goto the core router and look under /rout ospf routes and look at the route for 10.51.17. The state for that is inter area.

Dallas

inter-area routes cannot be filtered.

External route in ospf is one that is imported from other routing protocols (bgp.static,connected etc).

inter-area routes cannot be filtered.

External route in ospf is one that is imported from other routing protocols (bgp.static,connected etc).

I want to understand this clearly. Right now the only routing protocol I have is OSPF. We have almost 4000 routes. I just looked and 3/4 of the routes are external and the rest are network/summary network/router. I am trying to learn how they were decide to be that certain network type. So I can decide how I can rebuild my network.

I started building multiple areas and it looks like those routes became intra area routes. My main purpuse of the 2nd are is to cut down on routes so I can use mpls without maxing out memory in the forwarding table. I got the 2nd area working great but the /32 from the pppoes are propergating to the backbone. I dont want each of the /32 propergated. Thats why I am trying to figure out how to use routing filter and area2.

Back to your statement. You said,"External route in ospf is one that is imported from other routing protocols (bgp.static,connected etc)? static,connected? I dont know what you ment by static and connected. Those are not protocols right? Thanks for helping.

Dallas

If you are using the redistribute connected or static to get the networks into OSPF, that is likely the reason they are external. You will need to advertise using the network command to get rid of the Type 5 LSA.

Thanks for that. This morning something clicked when thinking the overall network design. I wont need to be advertising /32 for the pppoe over the ospf anyways. I will just use ospf for routing the network not the customers. (I say to myself duhh). Thanks again everyone I have learned a lot here.

Dallas