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DHCP Renew Fails on Win 2008 R2 SP1 Hyper-V when PRTG probe running

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This problem is a little convoluted, and I'm not quite sure where the root of the problem lies.

I have PRTG running on a Hyper-V VM running Win 2008 R2. This sits on a Hyper-V cluster. It has been running fine for several months. A couple of weeks ago I installed Windows SP1 on both the client and Hyper-V host machines. Since then, the client machine has fallen off the network every 4 days. It loses it's DHCP assigned IP address replacing it with a 169 autoconfiguration IP. The only way I have found to get it's IP address back is a reboot of the VM.

If I try to do a manual DHCP renew with ipconfig /renew it generates an error "An error occurred while renewing interface...An attempt was made to access a socket in a way forbidden by its access permissions" and reverts to a 169 IP. My DHCP lease is set to 8 days, so I'm fairly sure that it's dropping connection after 4 days as this is 50% of the DHCP lease at which point it contacts the server to renew the lease.

I came accross http://support.microsoft.com/default.aspx?scid=kb;EN-US;974909 which provides a hotfix for pre SP1 Hyper-V machines which lose network connectivity when under high network load, so I suspect this may be a related problem. But since the files in the hotfix are considerably older than those in SP1, I'm reluctant to apply the hotfix.

If I disable the PRTG probe service, the problem seems to go away, so I suspect it's the large number of connections PRTG makes (I have a couple of hundred sensors) that's causing the problem.

Has anyone come accross this issue or have a fix?

Thanks,

Tim

169 dhcp prtg windows-2008-r2-sp1

Created on Mar 1, 2011 2:13:28 PM



1 Reply

Votes:

0

I've done a little more troubleshooting here. By reducing my DHCP least time I've confirmed that the server only loses its IP when PRTG probe is running.

The hotfix I mentioned above is included in SP1, so that's no help. Thinking that the problem might be related to SP1, I uninstalled this from both the guest VM and the Hyper-V host server, but the problem remains.

Created on Mar 2, 2011 1:28:10 PM




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