I'm running some HP Proliant DL360 G6 servers with vmware esxi, and I have a Synology Diskstation appliance, all connected to a layer3 switch "Cisco Catalyst 4500" in a specific vlan and every server has its own static ip address with no dhcp pools configured in this network.
The problem is that sometimes when I call the Diskstation ip address a vmware server, specifically the first server, responds although it has its own static ip and doesn't conflict with any other server.
Sometimes the Diskstation responds and it works.
What could the cause be? it first looked to me like an ip conflict or something cause of observed ip range in vmware, but still can't see how to solve this problem.
You either have an IP conflict (likely) or a MAC address conflict. There is no other reasonable way for this to occur.
If you really can't find the IP conflict, try sending out an arping to the target IP address using the
arpingutility for linux, or something like that. Watch what comes back. If you want you can even run wireshark and watch the traffic.Chances are you forgot to change MAC addresses when cloning VMs, or assigned one IP address to many things.
Because you can intermittently connect to it with the vsphere client, as MDMarra says, chances are the conflict is between your diskstation and the management interface of your ESXi server. Check this in the ESXi server's console; it is displayed on the default screen.