LTM pair split between two remote sites - routing issue
I've configured an LTM active/standby pair across two sites with our primary site being active and the standby unit at our DR location.
The site's are separate by layer 3 links so I've used L2TPv3 to tunnel a load balanced network between the sites, in addition to tunnelling the fail-over network.
The devices work fine and I am able to config sync them.
My issue arrives when configuring pool members.
For example, the active LTM is directly connected to a server network on the 172.16.0.0/16 subnet.
I can add pool members and the LTM can see them without issue.
The standby LTM has connectivity to another subnet for example 172.17.0.0/16.
The standby LTM see's only it's directly connected pool member and not the pool members at the primary site, likewise the active LTM can only see pool members local to it's location.
Clearly this is a routing issue, the active LTM does not know how to get to 172.17.0.0 and the standby LTM does not know how to get to the primary LTM.
I've tried adding static routes to the standby LTM for the 172.16.0.0 subnet via the web UI, but this errors on config sync as the routes are synchronised and I cannot add a static route to the active LTM for a network to which it is directly connected.
My question is if it is possible to have separate routing configurations on each device?
I could quickly solve the issue by placing the servers in the load-balanced subnet that is tunnelled between both sites, but my intention was to only have the VIPs placed in this network for security reasons.