ospf failover question

liven

here is the config:

Routers A and B are core devices

Routers C and D are edge/CPE devices.


Routers A and B are redundant with each other and so are C and D (hsrp or VRRP).

A runs OSPF with C

B runs OSPF with D

C and D are redundant down to a LAN, again HSRP or VRRP.

Is it possible to have routes learned or advertised to the core devices only show up on the device that is paired with the CPE device that is active?

for example, if C is the Master/active CPE device, is it possible for OSPF learned routes to only show up on A. And when D becomes master the routes will show up on C?

We do this where I work, but we are not using Cisco devices. I can get the failover to work perfectly with Metrics. I just have better metrics on the primary device. But the OSPF routes exist in both A and B all the time.

Or would it be possible for the CPE devices to not advertise OSPF routes unless there were the active/master device?

Thanks!!!

kryolla

HSRP is for default gateway redundancy and has nothing to do with routing protocols and OSPF routers in the same area needs to have the same LSDB so all 4 routers will have the same topology so I dont think there is a way to filter out LSA between B and D when B is not active then once it becomes active to flood the LSAs to D so D will have routes. I dont think there is a way for HSRP to communicate that with OSPF. Do A and B have connectivity and what routers are upstream from them. HTH

liven

kryolla wrote: »

HSRP is for default gateway redundancy and has nothing to do with routing protocols and OSPF routers in the same area needs to have the same LSDB so all 4 routers will have the same topology. HTH

I am fully aware that HSRP has nothing to do with the routing protocols.

We run nortel devices currently.


When side A is up and active OSPF routes show up there and not on side B...

I am replacing the nortel CPE devices with cisco... I can get the failover setup to work, the only difference is that the routes show up on A and B. Everything appears to work exactly the same, I am just trying to make it as close to the original config/behavior as it was when it was all nortel.

Sure it might not be possible, but if anyone has any ideas on how I might be able to do this please share.

kryolla

liven wrote: »

I am fully aware that HSRP has nothing to do with the routing protocols.

We run nortel devices currently.


When side A is up and active OSPF routes show up there and not on side B...

I am replacing the nortel CPE devices with cisco... I can get the failover setup to work, the only difference is that the routes show up on A and B. Everything appears to work exactly the same, I am just trying to make it as close to the original config/behavior as it was when it was all nortel.

Sure it might not be possible, but if anyone has any ideas on how I might be able to do this please share.

how are OSPF routes not showing up on B is there no LSAs on B and what links do A and B have beside the links to C and D?

liven

kryolla wrote: »

how are OSPF routes not showing up on B is there no LSAs on B and what links do A and B have beside the links to C and D?

A and B are the closet core devices in a global network. They are directly connected to each other and learn routes from each other.

They run VPNs for each customer, but not in the sense of an IPSEC vpn, more like a VRF. Basically individual routing tables for each customer.

Ospf routes are showing up on B, just not from the directly connected CPE device D. Unless you admin down the circuit, pvc, or interfaces on the primary CPE. Then presto OSPF routes that were present on A are no longer there and are now present on B.


I have tried for hours to mimic this behavior with Cisco CPE devices but I just can't get it to work...

kryolla

how is CE not sending routes to PE. Are there OSPF peering between the CE routers on the same lan segment and does the non-active CE have routes

kryolla

if you know how the existing ospf config works then implementing it on a cisco router isn't any different since its an open standard. I think you need to get more familiar with OSPF