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Cisco UCS, VLAN 1, and Disjointed L2 Networks

So I'm tracking on how the default VLAN 1 is allowed on all uplinks in Disjointed L2 Network configs, but what if VLAN 1 was not the default or Native VLAN on the UCS? What if we used a different Native VLAN and started tagging VLAN 1? Is the rule that the default or Native VLAN is the one that's trunked on all uplinks or is it always VLAN 1 no matter what? The documentation states "default VLAN 1" and doesn't address my scenario. Thanks!

 

edit: if I had my way, I wouldn't use VLAN 1 anyways, but I don't always get my way :)

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Beginner

Re: Cisco UCS, VLAN 1, and Disjointed L2 Networks

Not sure if I am getting your question correctly.

 

Yes by default VLAN 1 is allowed on all uplinks of fabric as well as in the DL2 network and it cannot be segregated to any of the fabric uplink port or port-channel. You can use another Vlan as a native vlan but you need to define the same at the vnic level (South bound traffic). By default Vlan 1 will be set as native on all the uplinks.

 

The FI will never receive any untagged traffic either it will receive the traffic with tagged Vlan 1 by default or if we have defined any other native vlan over the vnic let say 10 then the traffic will be tagged as 10.

 

Can you briefly describe exactly what documentation you are looking for and if you can elaborate your question?

 

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Beginner

Re: Cisco UCS, VLAN 1, and Disjointed L2 Networks

Is VLAN 1 still trunked on all uplinks in a DL2 network if I start tagging it? Let's say I set VLAN 20 as the Native VLAN and begin tagging VLAN 1. Is VLAN 1 still trunked on all uplinks in the DL2 networks?

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Beginner

Re: Cisco UCS, VLAN 1, and Disjointed L2 Networks

Is VLAN 1 still trunked on all uplinks in a DL2 network if I start tagging it?

Ans:- By default if no vlan is set to native then yes the VLAN 1 will still be tagged on all uplinks.

Let's say I set VLAN 20 as the Native VLAN and begin tagging VLAN 1.

Ans:- Please understand in this way in UCS we set the native vlan on the vnic's which is south bound traffic so if I open the vnic properties or template and check the vlan I will find vlan default which is vlan 1 and other vlan let suppose we have vlan 20 over here we can make it as a Native and all the untagged traffic will be tagged with Vlan 20 on them instead of vlan 1.

Is VLAN 1 still trunked on all uplinks in the DL2 networks?

The answer is yes.

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Beginner

Re: Cisco UCS, VLAN 1, and Disjointed L2 Networks

Ok, I think I understand. It sounds like there's no way to trunk VLAN 1 only over one set of uplinks in a Disjointed Layer 2 Network, whether or not VLAN 1 is tagged or untagged or whether we use a different native VLAN or not. Is that correct?

 

 

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