No.
You must use unique IP.

With ESXi you can have the same vmkernel interface for both vMotion and Management? Yes, but is better to use different interface.

Also the IPs must be unique on all ESX!

Andre

I suggest to keep the COS IP, or you have to disconnect and reconnect in your VC, and also change all DNS / hosts resolutions.
Create only a vmkernel dedicated to VMotion.

Andre

I suggest to keep it by default, and only use DNS server for lot of ESX.
For a couple of ESX you can put all COS IP with first the FQDN and then the short name.

Andre

The purpose of /etc/hosts entries is to protect from DNS failure and your HA relies on DNS. If your DNS doesn't work, then you still be able to function properly using /etc/host entries which should be:

IP addresss FQDN Shortname
10.10.10.3 esx01.domain.com esx01

Host entries are good for small environments, if you have over 50+ ESX hosts environment, I'm sure your DNS infrastructure should be up 99.999% of the time so don't worry about it. But if you have less then 10 hosts, you can put all entries host file and then SCP to all hosts.

If you found this information useful, please consider awarding points for "Correct" or "Helpful". Thanks!!!

Regards,

Stefan Nguyen
VMware vExpert 2009
iGeek Systems Inc.
VMware, Citrix, Microsoft Consultant