kronnic
Contributor
Contributor

VLAN issue with additional NIC for ESXI guest

Hi all,

I have an ESXI host with one physical NIC which is attached a a vSwitch with 4 port groups, 1 which is native the other 3 are VLAN tagged.

One guest has 4 NICs configured fom the port groups above (minus 1 ) and another from a 2nd vSwitch (no phtsical NIC). It is currently working as expected. However, when I add an additional NIC from a VLAN tagged port group to the guest, it is as if the VLAN associated with those port groups are swapped or random.

The indication of this is:

- The DHCP issued address for one NIC is from a network connected to another NIC

- A series of ARP errors on the guest

If I remove the added NIC, the issue is rolled back.

0 Kudos
7 Replies
planetshoots
Contributor
Contributor

Hi

Seems like routing issue..check the route and if needed add a static route!!

0 Kudos
kronnic
Contributor
Contributor

How so? Regardless of which port group I assign to the additional NIC, the issue occurs.

0 Kudos
Sinorama
Enthusiast
Enthusiast

It would be simpler to follow if you show your vSwitch topology and port configuration on the physical switch.

0 Kudos
kronnic
Contributor
Contributor

This is the vSwitch topology. It has a physical NIC and VLANs 2,3 and 0 are connected to VMs.

The issue occurs when I add the Guest Network to a VM:

- A VM issues a DHCP request on the External Network and receives a response from a DHCP server on the Internal Network

- If I remove the Guest Network from the VM, the issue reverts

Screenshot from 2018-08-03 07-17-11.png

0 Kudos
HassanAlKak88
Expert
Expert

Hello,

Kindly clarify the network IP addresses at vmnic level, do you configure a two gateways (routers) ?


Cheers,
vExpert2020-2019||vExpert-NSX2020||VCIX6-NV||VCAP-NV-DCV||VCP-NV-DC-CMA||CCNA-R&S
Twitter: @KakHassan
LinkedIn: linkedin.com/in/hassanalkak
0 Kudos
RonnyNorway
Contributor
Contributor

Also check that you have defined correct IP helper on the switch, otherwise you might just get the default range assigned from the DHCP server

0 Kudos
kronnic
Contributor
Contributor

I'm not sure what this has to do with layer 3 given it currently works and the issue only occurs when the additional NIC is added to the VM.

0 Kudos