none
One HV Guest Failing to get DHCP Address

    Question

  • Windows Server 2012 R2 Hyper-V Host (HV1) has two (2) Hyper-V Guest servers, DC1 and APP1, both are Server 2012 R2.   These are going to replace the existing "SERVER1" that is end of life and needs to go away.  SERVER1 is Server 2008R2, runs internal DNS, DHCP, and has some shared files that end users access (spreadsheets and the like.)  

    Network is 10.100.1.0/24, set up by their previous IT service provider. 

    For reasons that are too lengthy to get into, I have both set (at the moment) to have IPs assigned by DHCP.  

    HV1 has 4 NICs for use, and I paired them into teams: HOST-TEAM is NIC 1 and 2.  HV-TEAM is NIC 3 and 4.  

    Created a Hyper-V switch in Hyper-V Management Console, using the HV-TEAM pair.  Confirmed that the "Allow management operating system to share this adapter" is OFF.  

    Both DC1 and APP1 Network Adapters are set to "Obtain automatically."  

    Here's the strange part, and the source of my question: APP1 is getting a DHCP address just fine.  But DC1 is not... it's picking up an APIPA address.  

    If I un-team the host NICs and assign NIC3 to APP1 and NIC4 to DC1, I get the same results: APP1 gets DHCP, DC1 does not.  If I switch those around (NIC3 goes to DC1, NIC4 goes to APP1), I get the same results. 

    I verified the Ethernet cables from the host to the switch are good.  Verified no port security on the switch port.  DHCP Helper on switch is OFF.  Running a Wireshark on the DC1 connection shows that there is no DHCP OFFER in reply to several DISCOVER attempts.  DC1 has DHCP Server service stopped and disabled, and DHCP Client is started.  Everything has been rebooted.  No change.   Hyper-V Switch has been deleted and rebuilt.  No change. 

    Running “Get-NetAdapter | sort MacAddress” in Powershell on the host reveals no duplicate MAC addresses.  Windows Firewall turned off.  No change.  

    For the moment, I just set DC1 to a static IP, which is going to change in a couple days once I get it up as the PDC and DHCP server, but I'm genuinely curious why this one VM would fail to get a DHCP address when the other does, and they are both set up exactly the same.  Has to be something in the OS, but what?  

    Thanks for any feedback you might have.  


    • Edited by Reno316 Tuesday, March 21, 2017 5:31 PM Typo
    Tuesday, March 21, 2017 5:31 PM

All replies

  • Might try as a test with static address, default gateway and DNS, then see if you can ping the DHCP server. (as a side note; surprised to see you have a DC with DHCP assigned address)

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Tuesday, March 21, 2017 7:29 PM
  • "as a side note; surprised to see you have a DC with DHCP assigned address"

    *** 
    Yeah, it's just a temporary thing.  I built the HV host and guest VMs in my office, before we knew the IP schema at the client (their previous IT vendor was not giving us any information, whether out of spite or for other reasons...)

    My goal was "Just get the host on the network, get the guests connected, then start migrating stuff once the other vendor gets us what we need."  Much of this was due to the customer pushing hard, and it's a decent contract for our small operation, so I did what I had to do.

    It's going to get a static once I get it promo'd to PDC, shut down the other server, etc.

    Tuesday, March 21, 2017 8:00 PM

  • Yeah, it's just a temporary thing.  

    I'd still want to confirm the route exists. Simple method would be assign a static ip then ping / tracert, etc.

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Tuesday, March 21, 2017 8:08 PM
  • Done.  One hop, straight to the existing server. 

    Thanks for the feedback, Mr. Patrick.  I appreciate.

    Best,

    Jeff

    Tuesday, March 21, 2017 9:07 PM
  • Good to hear, so all is good?

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Tuesday, March 21, 2017 9:10 PM
  • Yes sir, other than the fact that I still have no earthly idea why it didn't pick up an address.  

    Best,

    Jeff

    Wednesday, March 22, 2017 2:01 PM
  • Good to hear, you're welcome.

     

     



    Regards, Dave Patrick ....
    Microsoft Certified Professional
    Microsoft MVP [Windows Server] Datacenter Management

    Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.

    Wednesday, March 22, 2017 2:06 PM
  • Hi,
    Are there any updates on the issue?
    You could mark the reply as answer if it is helpful.
    Best Regards,
    Leo

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Thursday, March 30, 2017 2:21 AM
    Moderator