Hi Duarte, I'm not sure if your situation is more complicated than mine. I have two dispatcher nodes in the HA setup, with real IPs say IPa, IPb. They share a floating/virtual IP, let's call it VIP. Both nodes listen to the VIP (not its real IP), and use the VIP as the dispatcher's socket. In this case the master node which has the VIP can always send OPTIONS pings fine. My problem was with the backup node, which doesn't have the VIP so fails to send OPTIONS pings. Joel Serrano gave a good suggestion: both nodes start up with polling disabled, and only when a node turns master it enables the polling. This has solved my problem. Cheers, Yufei