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Hyper-V Server Can Ping Default Gateway but VM Cannot

VM Unable to ping gateway.
Can ping VM host
VM host can ping gateway
Windows Server 2012 R2
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WORKS2011
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Is this a poweredge server with Broadcom NIC? Known issues with the NIC driver, Please check if the NIC driver is currrent.
When this happened to me I had to delete the VM NIC and the host virtual switch, install both back, restart DNS, run ipconfig /flushdns on both and test.
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@WORKS2011,


Yes, it is a poweredge with Broadcom NIC.

I am finding now that I cannot ping the VM Host server on the Physical interface that is connected to that switch, but I can ping and remote to it via another.
It's a known issue with the 2012 R2 Servers and Broadcom NIC cards. Does it show a firmware or driver update needed for the NIC? If so I recommend trying to update this first. If it works you should be fine. If it doesn't then you have to play around with the binding on the NIC's and virtual switch. It's a pain. I've spent hours with Microsoft on this and they just confirm 2012R2 and Broadcom have many reported issues. I tried working with Broadcom but they didn't provide any feedback.

Good news haven't seen this issue at all with 2016 server, glad it's been resolved with the next OS.
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ASKER

It says that I have the best driver already installed.
Let me try what you suggested above and see..

Any idea as to what caused the issue?
because I left the server working perfectly last night and I come this, morning, it just stopped without me having changed anything.
That's how it happened for me. Usually updates were installed and this caused the issue. Something about the bindings between the host and VM's doesn't get reset or cleared out and causes the issue.

One of the challenges when this happened was the host and VM's became so sluggish I could barely manage them. To get around this I manually configured the NIC's via an elevated command prompt. You may have luck setting the NIC's back to their settings prior to this happening.

To do so via a command prompt do the following: To change IP and default gateway: netsh int ip set address "local area connection" static 192.168.0.123 255.255.255.0 192.168.0.254 1

To change DNS: netsh int ip set dns "local area connection" static 192.168.0.254 primary
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Updates were mainly the issue for us. We turned off automatic updates and manually downloaded and installed once a month until we upgraded to Server 2016.
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I have two very thorough EE articles on all things Hyper-V:

Some Hyper-V Hardware and Software Best Practices
Practical Hyper-V Performance Expectations

The first article explains how to disable Virtual Machine Queues with Broadcom NIC ports. The "problem" will come back if that was indeed the source of the issue. Note that if the Broadcom driver gets updated it will flip the setting back.

We can have a boo at the network setup if you like:
Get-NetAdapter
Get-NetLbfoTeam
Get-VMSwitch
Get-VMNetworkAdapter *

Open in new window

These get done in an elevated PowerShell. There may be a configuration issue as well.