tracking interfaces

[pcromwell]

I have an OSPF deployment (small) with 2 routers each router has 2 feeds to 2 switches and each router has 2 BGP feeds to 2 Carrier routers.

If we disable our primary router feed, Incoming traffic from the carrier falls over perfectly but we cannot make outgoing connections as I have a static default route from the switches that point to the primary router. Should I be using OSPF to work out the default route has changed or do I put in different statc routes manually with weighting/costs?

Someone also mentioned to me to use tracking on the routers, to track the interfaces. can anyone show me how this would work?

[Georg Pauwen]

Hello,

the tracking would actually be done on the switches. Basically, you track your connection to the primary router, and if that fails, another (floating) static route to the secondary router will be activated.

If you have never done this before, it can become a bit tricky. If you post the configs of the routers and the switches, we can fill in the necessary bits and pieces...

[pcromwell]

Thank you Georg and Paul for the swift replies. I have attached a topology with the example addresses. I have OSPF running on the switch stack and the routers for all interfaces.

Primary (default) outbound route is from switch to rt1 172.16.10.1 and default inbound from carrier comes in on .16

Secondary route comes in on .22 and outbound secondary default would be 30.1  with 20.1 and 40.1 also being on standby should a complete switch be lost in the stack. So whatever is the best solution

for this topology would be greatly appreciated

many thanks 

[paul driver]

Hello

I have a static default route from the switches that point to the primary router

Tracking is one possible way and the most simplistic

Another possibility would be running  a FHRP such as HRSP, this way you can have a consistent static default route pointing to a virtual nexthop ip address then if any outage upstream is incurred your default is still consistent and valid

However if your L3 switch(s) supports ospf then it would be best to have a default advertised to them by a dynamic routing protocol instead of statically defined as you can then control the advertisement by ospf costing, metrics etc. in case of outage to your ISP routers.

Can please post a topology of your network and then the options can become much clearer.

res
Paul