We have two servers, both with static IP addresses (Server A ends .221 and Server B ends .222) that are suddenly reporting as having the same MAC address. Both servers are running ESXi and ESXi recognises the MAC addresses correctly, Server A ending 6a and Server B ending 5c.
After we started experiencing major problems yesterday we looked into things and the router, when I do an IP scan shows that both IP addresses are tied to the identical MAC address of Server A.
Does this look like the router has been compromised and there is some ARP spoofing going on, or could there be another cause?