In VSS SW6500´s - Configuring a L3 PortChannel subinterface using an existent VLAN ID

[jssalgado]

This is the situation: let´s say that a VSS (SW6500´s) has a VLAN 37 passing in a few TRUNKS working perfectly. But now, we need to configure a PortChannel L3 (Let´s say PortChannel 100) and also need to create a sub interface there such as "interface PortChannel 100.37 with a given ip address in the subInterface. Now, the question is: when configuring command "encapsulation dot1Q" within the subinterface, can we use ID 37 ?, will this be allowed by the switch? VSS 6500

[Francesco Molino]

Hi

Not sure I understand your question. If you have vlan 37 into your vlan database, sure you can use it on a sub-interface.
Did you try and get an error?

[brselzer · Accepted solution]

Hello,

If you have a vlan in your vlan datadase, it is not eligible for a sub interface:

6500(config-subif)#encapsulation dot1q 50
Command rejected: VLAN 50 not available

Just use a trunk port with an SVI instead. 

Hope that helps!

[Francesco Molino]

My bad, I forget to ask which supervisor it was used on the 6500 chassis.
Because with SUP720-10G it wasn't possible. But on 6800 it is working.

[jssalgado]

Good point Francesco, We have a SW6509 equipped with "Supervisor Engine 2T 10GE w/ CTS (Acti VS-SUP2T-10G"., as in the 6800 Switch. Please, let me ask one more question asuming I may configure the subinterface using an already taken ID,... will the traffic coming in VLAN 37 and subinterface (ID 37) be in the same broadcast domain or these traffics would be in different brodcast domains?

Thanks so much for taking time to answer this.

[Francesco Molino]

You need to test with sup2t. I checked the one i have access in lab for a new deployment and it's a sup6t.
Then the answer to your question is yes.
I don't know what you're trying to achieve but it would better to use SVI unless you require a physical interface for a specific use case.

[jssalgado]

Thanks so much. This is what I thought it would be and you proved it as I saw the outcome for the command "encapsulation dot1q".   But Francesco Molino says it depends on the SUP (With SUP720-10G it wasn't possible to configure. But on 6800 it is working).

Thanks to both of you for the contribution.