Today I had to debug a complex problem with colliding subnets (reason: customer bridged his network to the public wifi).
(Both networks are not related - different physical networks)
Because of some ebtables rules, the customers network was working fine. On the other hand, the public wifi (-> KEA) provided IPs to new devices that were also in use in the customers network (confusing the MAC address tables).
If these new devices got an IP that fits into the customers network (because they overlap - for example: 10.201.3.33), it was completely unreachable to all clients that were not connected to the same wifi node.
Is it possible to filter out such scenarios?
ARP might not work as the broadcast address differs.