vCenter and Skyline Health Problem
If you enable CEIP on a vCenter, there will for the “some” installation come a alert that the UDP heartbeat not working.
I have seen this in multiple installations, and do not see any disconnects, or any other problems.
I have check driver/firmware for compatibility, NICs in en ESXi hosts port for packets drop/errors, the switch ports for packets drops/error, and none of them had any issue. So this looks like a bug.
I the Skyline Health you ca see this warning:
This issue occurs when the UDP heartbeat message sent by ESX/ESXi host is not received by vCenter Server. if vCenter Server does not receive the UDP heartbeat message, it treats the host as not responding. ESX/ESXi host send heartbeats every 10 seconds and vCenter Server has a window of 60 seconds to receive the heartbeats. This behavior can be an indication of a congested network between the ESX/ESXi host and vCenter Server.
The solution is the change the timeout from the default 60 and to 120, in the vCenter advanced setting.
config.vpxd.heartbeat.notRespondingTimeout = 120
See the VMware KB here.
NOTE: I did not restart the service, and looks likes it works.