[Xorp-users] Example config files for connecting different OSPF areas?

[Ben Greear]

Kristian Larsson wrote:

> It's basically the same as with only one area..
> with the exception that you have more than one
> area ;)
> Have you run into any problems?

Ok, this is probably another basic misunderstanding of OSPF on my part:

I have router 1, with 2 interfaces: 10.3.0.1/24, 10.3.1.5/24 and area 0.0.0.1
A third interface is in area 0.0.0.0
That interface connects to router 2, which in turn connects to
router 3.  All interfaces in R2, R3 are area 0.0.0.0

I was hoping that the routing table for R2 would
show something like:

10.3.0.0/16 via 10.0.0.1 dev rddVR1  proto xorp  metric 2 notify

(ie, consolidate the two 10.3 subnets into a single route).

Instead, I see:

10.3.0.0/24 via 10.0.0.1 dev rddVR1  proto xorp  metric 2 notify
10.3.1.0/24 via 10.0.0.1 dev rddVR1  proto xorp  metric 2 notify


Now, after a bit more thinking..this sounds like it couldn't really
work since there may be other 10.3.x.x subnets elsewhere.  But, is there
a way to somehow tell it that we have all 10.3.x.x/24 subnets on or
behind R1 so that only the 10.3.0.0/16 route is propagated to the
rest of the OSPF network?

My config for R1 is below, if that helps.

Thanks,
Ben


     protocols {
         ospf4 {
             router-id: 127.1.0.2
             traceoptions {
                 flag {
                     all {
                     }
                 }
             }
             area 0.0.0.0 {
                 interface rddVR0 {
                     vif rddVR0 {
                         address 10.0.0.1 {
                         }
                     }
                 }
             }
             area 0.0.0.1 {
                 interface rddVR3 {
                     vif rddVR3 {
                         address 10.3.1.5 {
                         }
                     }
                 }
                 interface br2 {
                     vif br2 {
                         address 10.3.0.1 {
                         }
                     }
                 }
             }
         }
         static {
             interface-route 0.0.0.0/0 {
                 next-hop-interface: "my_discard"
                 next-hop-vif: "my_discard"
             }
         }
     }
     fea {
         unicast-forwarding4 {
             table-id: 10002
         }
     }
     interfaces {
         interface "my_discard" {
             unreachable: true
             vif "my_discard" {
             }
         }
         interface rddVR0 {
             vif rddVR0 {
                 address 10.0.0.1 {
                     prefix-length: 24
                 }
             }
         }
         interface rddVR3 {
             vif rddVR3 {
                 address 10.3.1.5 {
                     prefix-length: 24
                 }
             }
         }
         interface br2 {
             vif br2 {
                 address 10.3.0.1 {
                     prefix-length: 24
                 }
             }
         }
     }

-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com