What are the expected network configurations across a deployment?

For example, is the Gatekeeper front interface expected to be in the same subnet as the back interface, a different subnet, or it does not matter?

Similarly, is the back interface expected to be in the same subnet as the Grantor interface, a different subnet, or does it not matter?

I ask because I have run into the following scenarios:

1. The Gatekeeper front interface is in subnet 1 and the back interface, Grantor interface, and destination are in subnet 2. When adding a prefix to the Gatekeeper FIB for subnet 2 (to forward packets to the destination through Grantor) in this setup, Gatekeeper cannot find a cached Ethernet header here:

https://github.com/AltraMayor/gatekeeper/blob/master/gk/main.c#L1528

2. Similar issue as above if the Gatekeeper front and back interfaces are in the same subnet.