IP SLA

[hy3rid]

We have 2 routers connecting to another Customer (CustB) for network 192.168.1.0/24. Static routes on both of the CustA routers to the 192.168.1 network. See attached for topology.

Notes:

- I don't have access to CustB routers

- Redistribution from CustB routers is NOT an option

- Created an IP SLA on both routers and tied to static routes

- Running EIGRP and redistributed static routes on both

- Increased the redistribution seed metric from RTR2 to have all traffic go through RTR1

Problem:

SLA and redistribution into EIGRP is working. But when looking at RTR2 routing table. Obviously its own static route takes precedence over the redistributed route because of the AD. 

1. What are my option here to have all traffic go through RTR1 (even from RTR2) unless RTR1 is down? Is changing the static routes AD the only option?

2. Is there a better way to accomplish what I am trying to do?

[Simon Darlington]

So with the restrictions you've stated, then you have a working solution for CUSTA-LAB routing via CUSTA-RTR1 towards 192.168.1.0/24 under normal operation. Under failure of CUSTA-RTR1 you're using static routes and IP SLA to route via CUSTA-RTR2 to reach 192.168.1.0/24.

Additionally you would like traffic from CUSTA-RTR2 to route clockwise via CUSTA-RTR1 to destination 192.168.1.0/24. Raising the AD of the static route for 192.168.1.0/24 which you've mentioned is a great solution. Should the redistributed static on CUSTA-RTR1 get withdrawn under failure, then this will ensure the (now floating) static route on CUSTA-RTR2 will be installed in the rib on CUSTA-RTR2, which is required to route traffic onwards to 192.168.1.0/24.

Another solution would be to use longest match routing on CUSTA-RTR1. Split the /24 destination subnet into two routes - 192.168.1.0/25 and 192.168.1.128/25 - and configure these as static routes instead on CUSTA-RTR1 only tied to your IPSLA. CUSTA-RTR2 will use these eigrp /25 routes under normal operation and it's static route to the /24 under failure.

Hope this helps. Please rate helpful posts.