Hyper-V Guest / Networking Issue (Guest VM cannot connect)

Question

Hello Community, I am facing the following issue: Host hardware server 2019 standard server with guest virtual machine (same system 2019 standard) and one workstation with win 10 I configured such a combo many many many times and never faced such a problem. Additionally, I have to add that I am using VM guest which is taken from an "Image" and the host server and workstation are also configured accordingly to the same "script" - so it is tested configuration - till now. Everything has to be added to the clients existing Active Directory domain The client already added a host server to this domain along with the workstation - and this worked. With hyper V he has got no experience so it was done remotely and as usual, I created Virtual External Switch which was then added to this VM, and here where the problem starts. - normally it works right away but not this time. Virtual Switch sends and receives packets normally (checked in host system) but virtual adapter in VM it says "no internet" and it is dead nothing 0 packets received I tried with disabling firewall, ICMS in inboud rules, I tried with private/domain network profiles.... literally everything I was able to find in web similar to this situation but nothing... it looks like there is no DHCP active in his network and he assigned the following IP configuration to the host server Host server IP 172.20.32.120 Gateway: 172.20.32.254 DNS: 172.20.249.1 and .2 for the virtual machine, he (said) assigned 172.20.32.123, so everything typed in manually into the VM adapter .. but still dead. the only thing which VM can do is ping the host server (172.20.32.120) and vice versa. so it looks like it "stuck" on the Virtual Switch but like I said this configuration worked many many times already is it possible that there is something blocked for example in the client's network (like router firewall etc) which blocks this .123 VM IP to connect? any help/hints will be much appreciated

Answer 1

Not clear at all what guests are running? domain controller? or member servers?

Please run;

Dcdiag /v /c /d /e /s:%computername% >c:\dcdiag.log
repadmin /showrepl >C:\repl.txt
ipconfig /all > C:\dc1.txt
ipconfig /all > C:\dc2.txt
netsh advfirewall monitor show currentprofile>C:\dc1profile.txt
netsh advfirewall monitor show currentprofile>C:\dc2profile.txt
ipconfig /all > C:\problemmember.txt
netsh advfirewall monitor show currentprofile>C:\problemmemberprofile.txt

then put unzipped text files up on OneDrive and share a link.

Answer 2

Hi ,

Virtual Switch sends and receives packets normally (checked in host system) but virtual adapter in VM it says "no internet" and it is dead nothing 0 packets received I tried with disabling firewall, ICMS in inboud rules, I tried with private/domain network profiles....

1.Did other VMs connect to this external virtual switch have the same problem? If yes, try to re-create External Virtual Switch again. See if the issue still happens.

2.If the issue is only occurred on this VM. Please try to remove External virtual switch and then re-add this External virtual switch for VM again. Then check if the problems still happens.

3.If the above methods still don't work, right-click VM's adapter and run diagnose to see if it can detect and repair any problem.

4.Did you install any third-party software on your VM? If yes, please temporally disable them to do a test.

Best Regards,

Candy

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Answer 3

Hey short follow up:

it was on the client's side that he forget to add the Virtual Machine IP to the "allowed" connections list in his network. (whatever he meant by this) It was remote installation with a bit of language barrier from the clients side so there was not many test possibilities I could run..

long story short it works and thanks for the comments and ideas to help!