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waynebunch
Contributor
Contributor

Can't connect VM to network with new distribution group port (New VLAN),

Hello,

I have recently created a new VLAN (45) via new distributed port group. As far as I can tell everything is correct. 

  1. Clicking on the distributed port group shows VM "Link Up", correct MAC and name.
  2. Distributed Switch > Configure > Topology, I see that my VM is connected to correct uplink.
  3. VM network adapter, VLAN 45 is selected.
  4. I have Meraki switches, and the trunk allows all VLANs

This new vlan is basically an exact copy of a VLAN(4) that I have, and 4 works correctly.  If I change my VM network adapter to VLAN4 or VLAN10, the network comes right up.  But as soon as I change to VLAN45, the network is "unidentified" and DHCP doesn't work.  Even if I give it a static IP in VLAN 45 ip range, it does nothing.  

I've tried doing a packet capture on the port the VM resides on from the Meraki switch, but I don't see any DHCP requests, which makes me think this is a vSphere issue.  I'm not sure how to troubleshoot, seems like this should be really simple.

Any thoughts?

*Update

Did a packet capture on the host, do see DHCP packets on the switchport of host, yet still nothing at the physical switch port.

vmnic0  -----X----> Meraki switch

I know connection is correct, I switch it to VLAN 10 and it immediately gets an IP. 
Verified DHCP server on the Meraki.

 

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mguidini
Enthusiast
Enthusiast

Hello,

- uplink2 (4 NIC adapters) - Contains 4 Network adapters connected to 4 different ports in your physical switch. Most likely one from each ESXi? Make sure you have VLAN 45 passing through the trunk for all of those 4 ports (even if aggregated).

- Isolate the virtual Layer 2 first and possible GuestOS issues. Create another virtual machine, place in the same portgroup and assign static IPs on both and try to ping each other. 

- Create another portgroup on VLAN 45 and place one of the VMs in there, but in a different ESXi host. That will force the traffic to go out through the uplink and back into the other portgroup in VLAN45 -  then you can control source and destination - that might facilitate your troubleshooting.

- Identify the gateway for this VLAN 45 subnet IP range (can be a vlan interface in the switch or a server in the network) and try to ping it from the virtual machines using static IP addresses. In the process, make sure you have a DHCP server for this subnet running and reachable from the virtual machines perspective.

 

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