Remove a OSPF area from router

[Djbucholtz]

We have a 2911 dual wan router and we would like to remove a OSPF area. For instance, the area is...

10.x.x.x 0.0.0.255 area 8000

Our primary OSPF is 

192.x.x.x 0.0.0.255 area 8000

How can we remove the 10.x.x.x and no longer use OSPF?

Example, we want to go from g1 on router to g1 on firewall. no longer use OSPF all together

[balaji.bandi]

we need a full configuration of OSPF to suggest best

or you can do as below if you like to remove the only the network from router OSPF (Hope this this was already added - 192.x.x.x 0.0.0.255 area 8000)

config t

router ospf XX (XX is where process name)

no 10.x.x.x 0.0.0.255 area 8000

!

end

keep an observer of the routes make sure nothing broke your network due to this.

[Djbucholtz]

what we want to do, is remote the ospf, and use CAT6 from GE0/0 to GE0/1 on our ASA5505 (next Hop)

or is it easier just to leave OSPF the way it is and only remove NETWORK 10.170.99.0 ???

[Giuseppe Larosa]

Hello @Djbucholtz ,

if you remove OSPF the firewall will need static routes with next-hop 10.99.1.2 for all the internal subnets including those behind other routers.

route 10.165.29.80 255.255.255.240 10.99.1.2  <inside>

route 10.161.19.0 255.255.255.0 10.99.1.2  <inside>

route 10.161.20.0 255.255.255.0 10.99.1.2  <inside>

and if it is used also

route 10.170.99.0 255.255.255.0 10.99.1.2  <inside>

if there are OSPF neighbors in subnet 10.170.99.0/24 you should also add static routes for all the subnets advertised by those devices.

If your ASA is currently speaking OSPF it learns all the internal subnets via OSPF.

>> and use CAT6 from GE0/0 to GE0/1 on our ASA5505 (next Hop)

This can be done even with OSPF active it is just a change in cabling

BUT in the first post you say you have two WAN routers if so the two WAN routers and the ASA gi0/1 have to be connected to three ports in the same VLAN to work

Hope to help

Giuseppe

[Djbucholtz]

What we want to do is remove OSPF all together. I want to go from GE0/1 on router to GE1/1 on my firewall. 

Right now both firewall and router are plugged into a switch. (hence the OSPF)

I want to got from switch to router to firewall via cabling and not OSPF

[Djbucholtz]

Also, we are not using the DUAL WAN. our configure should be

internal network >>>>>>>> SWITCH >>>>>>>>>>> ROUTER >>>>>>>>>>> FIREWALL >>>>>>>>>>> ISP

                                           2900                            2911                              asa5505                         COMCAST

[Giuseppe Larosa]

Hello @Djbucholtz ,

ok if the WAN router is only one you can use a direct cable to ASA. According to your screenshot the right interface should be gi0/0 on the WAN router.

Removing OSPF is also possible but all the notes about the internal networks to be added as static routes on ASA with next-hop = WAN router IP address   are still valid as explained in my previous post.

Hope to help

Giuseppe