In theory, we could scan through all link and VLAN data to find gateway.id values and remove them from the ID pool.
In practice, we'll just check for an overlap and report an error explaining that the gateway.id has to be set globally if
you want to set it to a low value.
Describe the bug
The gateway IP can overlap the node IP on the VLAN links when the gateway.id is not set globally (so it cannot be taken out of the ID pool).
Lab topology
Solutions
In theory, we could scan through all link and VLAN data to find gateway.id values and remove them from the ID pool.
In practice, we'll just check for an overlap and report an error explaining that the gateway.id has to be set globally if you want to set it to a low value.