Clarification needed: IP Pool for vApps

[danorama]

Ok, I know how to setup IP Pools for vApps, but what I don't understand is how vCenter knows which IP addresses are already in use. How is it aware? How does it work in conjuction with a DHCP server on the network?

The documentation doesn't go much in depth. I'd like to set it up in my lab along side my DHCP server.

[danorama]

Really? Nobody want's to take a crack at this?

I just want to know if there will be IP conflicts with DHCP and IP Pool handing out adreesses for VMs. Am I missing something?

[scott28tt]

As far as I'm aware vCenter Server has zero awareness of what DHCP-assigned or static IP addresses are in use on the rest of your network, it is down to the creator of the IP Pool to configure the addresses such that there are no conflicts.

This is no different to setting up a DHCP server - those I've setup in the past weren't aware of addresses being allocated by other DHCP servers or static addresses in use.

[danorama]

Thanks Scott. I wondered if vCenter had some underlying sophistication that I wasn't aware of. I guess the IP Pools need to be set up on different subnets to assign IP's.

[scott28tt]

Not necessarily separate subnets, but certainly separate addresses from those already in use on that network...

[danorama]

Well, vCenter doesn't allow me to set the range I want.

I understand that I'm to exclude the gateway and broadcast address, but if I want to start at 192.168.1.160#253 I get an error that the address must be an ordered, comma separated list. It only allows me to set the range as 192.168.1.2#253

My goal is to have my DHCP server responsible for one range while vCenter handle another within the same subnet. Is this done via command line or something? The GUI settings are limited.

Please advise

[scott28tt]

Perhaps it's not as flexible as I had imagined.