On PowerLInk look for Support Solution emc254967 - this is the main Primus for Host Agent issues - there is a section just for ESX - one of those will list all the solutions for ESX (emc241869). You may need to contact VMware to get the IP addresses correct - their agent may not be picking up the new IP's for the agent to pass to the array. See emc246939 - this may have some information.  glen
Scenario.  4 Hosts have rechanged IP (iSCSI connection). Under the connection tab , inside connection info. 3 shows correct IP. However one of the server after accepting the new IP after 5 minutes, jumps back to the old IP.  Steps taken so far.  Restarted the management server. Removed the host and connected it back, ( over here the same thing happens, that is it accepts the new IP , but goes bact to the old IP ) ESXi latest version is used hence no need of a Host Agent ( the info given by the Host team ) ( I too agree on this as the new IP is being picked up, though the HBA goes back to the old IP) VM Ware used. The packets from this perticular host is not dropped, that is the I/O s are passing fine.
Advice needed when a host changes its IP connected to an AX 4-5 .