Can someone explain this to me like I'm five? Our work configuration has me scratching my head. We've got two servers, both with the exact same IP. It's what we call our "HA IP", and as I understand it, the primary server uses it, and the secondary ignores it. How is this not a duplicate IP violation? I mean, if an ARP request is sent out, shouldn't both servers respond and eff up a routing table? Is there something in the IP stack in the OS that just "shuts off" the interface unless a heartbeat fails?