Hi all,
Set up as per the the following:
CPE --> LNS --> Core --> Upstream ISP ---- Datacentre 1
CPE --> LNS --> Core --> Upstream ISP ---- Datacentre 2
With the X-Connects in place between the two datacentres, everything is fully operational as expected. However, for DR testing, one of the critical tests is the pulling of the X-Connects to ensure both data centres can continue functioning separately in a seamless fashion.
CPE test address on Datcentre 1: 192.168.10.10
I have aggregated and advertised 192.168.10.0/24 to the upstream ISP. I pull the X-Connects to simulate complete link failure. I try to traceroute and ping the 192.168.10.10 device and get nothing.
Here is the strange part:
If I change the default route on the Core to point to the LNS rather than the other Core, it works. But the default is required for failover if we lose the upstream ISP.
So, the route for 192.168.10.10 exists in ISIS pointing to the correct egress interface. The LNS has the correct route in ISIS for 192.168.10.10.
The default route of 0.0.0.0/0 next-hop <other Core> is correct. If I point it to the other Core it does not work with no X-Connects, if I point it to the LNS, it works..... But then we would have no failover if we lose upstream ISP.
Question: If 192.168.10.10 exists in ISIS on the Core and on the LNS, pointing to the correct interfaces, why is the forwarding-table choosing the default route (it appears)? It should prefer the CORRECT ISIS route.....
Thanks