I have a situation where I am trying to setup a DR site for my current environment. My company has several routers that connect us to other institutions via VPN. So basically we send traffic to the vendors equipment and it tunnels back to the vendors. What I'm facing is I believe a limitation of AutoVPN.
Lets say the vendors subnet is 192.168.1.0/24. I need to be able to advertise that prefix from my DR Site and my primary DC. To my understanding, this is not possible with AutoVPN.
I am wondering, since my current primary DC uses a concentrator for AutoVPN, could I send it the route from my core routers via OSPF or iBGP and then manually enter the prefix on the other site? And if so, which site would actually be put into the AutoVPN table and which would be ignored?
My fallback option is using the API to write a script that fails us over by removing the prefix from the concentrator at the primary DC and adding it at the DR site.
To be able to advertise the same subnet you can not have a direct connection to it.
So if the production site was using 192.168.255.0/30 to connect to the layer3 switch at the site, and the DR site used 192.168.255.4/30 to connect to the layer3 switch at that site, then both MXs can advertise connectivity to 192.168.1.0/24.
I'm not completely sure on this one - but I believe whichever MX/network was added to the org first becomes the primary for the route.
The DR route is only used if the primary MX goes offline.