Can't ping between virtual servers on same host

[Bill_the_Cat]

I have an ESXi 5 host with 3 virtual copies of Windows Server 2008R2 running on them. The ESXi host is connected to my switch, which has the Windows 2008 R2 DC for my test network and my management laptop with VSphere connected to it as well. I can ping the host, laptop, and AD server from each of the individual virtual servers and can ping and RDP to all 3 from any other device not on that host, but I can not communicate between the three. I have Windows Firewall disabled on all three. I have no firewall, and all machines have a private IP address in the 10.0.0.X range. I've deleted and recreated the single virtual switch on the host that all 3 are contained on. I've been HIGHLY frustrated for the past 3 days on this. Why can't my VM's talk to each other?

[a_nut_in]

Hey Bill,

3 virtual copies of Windows Server 2008R2 running on them ... but I can not communicate between the three

How were the VM's created? Also when you mention you are unable to communicate between the three, do you mean just pings or even RDP does not work?

Are the VM's set to static IP or DHCP?

Can you run the following command on an elevated command prompt on each Windows 2008 machine and let me know if that helps?

So start - Run - CMD (right click run as administrator)

netsh advfirewall set allp state off

Regards

a

[Bill_the_Cat]

Thanks for the reply. We had an export of a working server that I imported into my host via sftp. I created 3 separate folders under my Datastore folder and imported the vmx file into each directory. I then renamed the vmx file to what the server's role would be. I used my management laptop to connect to the ESXi host and then browsed the data store for each virtual machine. This allowed me to boot each machine from the console tab in VSphere.

I set each server to its own static IP address. 10.0.0.100, 10.0.0.101, and 10.0.0.102.All 3 have the Windows Firewall Service completely disabled

My host is 10.0.0.2 and is connected to port 2 on my switch

My management laptop is 10.0.0.9 and is connected to port 3 on my switch

I have another ESXi host at 10.0.0.1 on port 1

I have my AD/DNS machine at 10.0.0.20 on port 9

As I said, I can ping and RDP from any other port on my switch to each virtual server. I can ping and RDP from each virtual server to any port on my switch. But nothing works between the three of the virtual servers. No ping, no RDP, and no ODBC connection (Those are the three things I tried).

Will run the command in a few minutes and update this post. Oh, and I turned off UAC for testing purposes.

*** Edit to add***

The command throws an error that the Windows Firewall Service is not enabled.

Also, just for informational purposes, when I am RDP to 10.0.0.100 and I ping 10.0.0.101, I get:

Reply from 10.0.0.100 destination host unreachable

I will re-enable the firewalls and run the command again to see if that fixes things.

***Edit again***

The command said "OK" but I still can't ping the other 2 servers when logged into one of them. I also looked at the arp cache after my ping attempt and it is not even seeing the IP address of the server I just tried to ping.

[vSchu · Accepted solution]

When you registered the VMs in ESX did you select Moved VM or Coiped VM? Go into the edit settings and look at the MAC addresses. My guess is that if you copied everythig (including the vmx files) then the MAC address is the same for all the VMs. You can shut down the machines and change the mac addresses to a static MAC address. You could also delete the nics one each, then add new nics. Remember to reconfigure the IP addresses on the box and delete the ghost nics after doing that.

Check this KB for changing mac address.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=507

Also, Can you log into the switch and look at the ARP table and see if the VMs are registering there.

[Bill_the_Cat]

Well, that was it! I changed the MAC address on two of the three machines in their config files, and voila! It works now!

Thanks for the help   :smileylaugh:

[vSchu]

You're welcome.