I am wondering whether it is possible to use IPv4 anycast to have multiple computers in the same IP subnet handle requests from other machines also in the same subnet.
I have two DNS servers on my LAN. Since I have learned that having two DNS servers on different IPs doesn't help redundancy (short reason: hosts will not always switch IPs and will keep using the IP of the offline server) I would like to set up some anycast IPs so that DNS requests will get sent to any DNS server that is up and running.
Looking into anycast, it is primarily used to route traffic to different sites using BGP, or to different destinations within a large site that has multiple routers. In my case there is only a single switch connecting everything and routing within the LAN only goes so far as ARP.
I can't find any information on how one might configure anycast in this situation. Can you simply assign two or more hosts the same IP address and the switch will figure out which port to send the packets to, dropping the port and clearing the ARP entry if the server goes offline? Will the hosts also reissue ARP requests if packets suddenly stop being responded to? Do you have to share a MAC address as well as an IP? Or is it impossible to use anycast with this setup and a routing protocol is required?