I am confused (IP Conflicts)

All,

I think I'm making a noobish mistake here. I have multiple sets of VM's in a ESXi stack, Each set is assigned a different VLAN but each set of VM's have the same IP address. On the physical switch I didn't configure a gateway or anything. It is strictly layer 2, no inter vlan routing at all.

One of the VM's (Windows Server 2008R2) in VLAN 1998 is getting an IP conflict with a VM (Win2k8R2) that is in VLAN 2000. I thought that since they are in different domains that this wouldn't happen. thoughts?

Find more posts tagged with

Save $250 on 2025 certification boot camps from Infosec!

Book now with code EOY2025

Button

Comments

OfWolfAndMan

If they're not routing outside of their local segment (VLAN) you could do it, but what would the point of that be?

HAMP

They must be trying to communicate outside of each of its own vlan?

higherho

The point of doing it this way is to provide students a sandbox enviroment to test / train in. The VM's that I was given were for a particular training session. I cloned this set 18 times (same IP scheme simply different VLANS inside my ESXi distributed switch). Only 1 VM is reported this IP conflict. The set of VM's can talk to each other (Domain controller, WSUS, Client, etc) but not to other student sets.

For some reason this one VM is having an IP conflict with another and I confirmed they are in their own VLANs and the physical switch only has a trunk port (standard when having multiple VLANS inside an ESXi stack). I made sure that the physical switch doesn't have the VLAN associated / created or an IP tied to it.

BlackBeret

The first mistake I made when setting up my VLAN's on esxi was I somehow had several sitting in the "all" VLAN as well.

higherho

BlackBeret wrote: »

The first mistake I made when setting up my VLAN's on esxi was I somehow had several sitting in the "all" VLAN as well.

That's the first thing I checked. I used Distributed switches so I went to the port groups for VM's that were complaining and the VLAN access states they are in different VLANs. I verified this by turning on the monitoring port capability and the MAC from the VM popped up on the port #. I checked this because I thought they were either in the same VLAN or something similar.

I went from VLAN 2000 down to VLAN 1970 and the Uplink ports are trunk ports. No other VM is reporting these issues