Hey everyone! I'm a junior sysadmin and have been on the job for about a month and a half. I encountered a tricky issue on our test host, which is an HP ProLiant DL360 Gen8, where we currently have a server running the LLM software for our database team. I was tasked with deploying a Windows 11 VM to create a golden template. However, once I connected the Windows 11 VM to the necessary VLAN in vCenter, the LLM VM lost its network connection. Additionally, both VMs seem to be exchanging MAC addresses and neither can connect anymore. The network team says it's not an issue on their side, and everything seems fine with the hardware in the server room. Can anyone advise on where I should focus my troubleshooting efforts to resolve this before the DBA team notices their LLM isn't functional? Thanks a lot!
3 Answers
This could be a MAC address conflict situation. If the VM was cloned from the same template as the LLM VM, they might have the same MAC address, causing ARP table corruption. Check each VM's network adapter settings in vCenter. If you spot duplicates, you can either manually assign a unique MAC address or remove and re-add the network adapter. Don't forget to clear the ARP cache on the LLM and possibly the switch as well.
You might want to check the VLAN settings for each VM's NIC and the configuration of your virtual switch, whether it's a standard or distributed switch. Are your ports trunked or set as access ports? This could definitely affect connectivity.
Make sure you look at your vSwitch load balancing settings. Sometimes, the load balancing method can cause issues when adding new VMs. What’s currently configured?
It's set to 'route based on originating virtual port'.
I’m using a virtual standard switch (vss), and the vmnic is fine until I add the Windows 11 VM to the VLAN. Then, the vmnic goes down and I need to get the network admin to reset it. We’re on trunk ports.