BladeSystem Virtual Connect

Virtual Connect "Multiply Networks" feature doesn't work problem.

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Virtual Connect "Multiply Networks" feature doesn't work problem.

Alexei needed some Virtual Connect help:




Hello, Experts


My customer has C7000  enclosure with Virtual Connect FlexFabric modules.

There are two physical network uplinks (X5, X6) configured active/active from each module.

I configured NIC3,4 as Management  network with VLAN 43 ( I use VLAN Tagging). It works.

I want configure NIC5,6 as Multiply Network and add only one network with VLAN 211. All NICs can’t connect to external network.

I configure NIC5,6 as Production network with VLAN 211 – and it works fine.


I did nothing on external switch (of course, I configured it before) and , I know, switch port configured for VLANs 43 and 211.




Input from John:

When you assign a single network to a nic, the VC module will “untag” the packet before sending it down to the nic. If you select multiple networks for a nic , the VC module will send down all packets “tagged” and the packets will have to be “untagged” at the OS level. So in your case for nics 5,6 at the OS level you will have to have Vlan 211 defined.

Why would you select “multiple networks” and then only choose 1 vlan?




Alexei replied: 

The customer asked us to do it “ for future use”




Greg's solution: 

Ok so what you should do is

1)      Define the Enet-connection( for nics 5-6)  as “Multiple-Networks” (as you have done)

2)      Add VLAN 211 to the connected vlan list AND

Set VLAN 211 as the native VLAN for the enet-connection(nic 5-6)


This should “untag” the any packet coming in from the from the core and retag any outgoing untagged packet with the VLAN 211 tag.




And Alexei was happy:

Hello, all

Thank you very much for your response.

Now we clearly  understand how it work and all work fine.




Comments or other suggestions for the customer?