Changing Management IP on ESX hosts

[JLoganAllegianc]

I have been working on a small project to change the IP for the management port on all of my esx hosts, and ran into a curious issue. I basically remove the host from vCenter, log into the console and change the IP, subnet, etc. I then update DNS and double-check that it is pinging both by IP and name on the new address. Then, after a reboot, I add it back into vCenter. Everything works as I expect except that I can still ping the old IP address. For example, one of the hosts was 10.16.32.159 and changed to 10.97.8.27. Yet I can still ping 32.159, though I cannot get an arp. I thought there may have been a conflict on the network, but when I shut that host down, the IP stops pinging. When it comes back up, the IP pings again. Any idea where the host could be hanging on to this IP?

[erikverbruggen]

That is indeed strange. I suspect you just changed the existing management vmkernel adapter? No other vmkernel adapters with the old IP exist?

Have you checked the output of the commands "esxcli network ip interface ipv4 get" and "esxcfg-vmknic -l"?

[JLoganAllegianc]

No other adapters show that I can see. Both commands return the management IP (10.97.8.x) and the private VLAN for vmotion (10.253.0.x). I see nothing out there in the 10.16.32.x range

[JLoganAllegianc · Accepted solution]

Apparently the issue lies on our network. This company (I am relatively new) was recently purchased by a larger organization and the networks flattened. The 10.16.32.x segment overlaps with the parent company, which is why I can ping; a tracert of the ping goes back to the parent company's network. So, frightening as it is that they are okay with this, not a vCenter-specific issue.