Trunking and VLANs

[Anders_35]

I'm looking at a practice exam for the Adaptive EDGE fundamentals test. There are a few errors in the test, but one question has got me doubting:

Basically, the question is: if your port XX is a tagged member of VLAN yy, and you add it to a trunk, what's the effect on VLAN yy?

The answer given is that the port will continue to forward VLAN yy, while the rest of the trunk ports will not.

Is this correct? I thought only the whole trunk, not it's individual ports, could have VLAN memberships.

Cheers,
Anders :)

[Matt Hobbs · Accepted solution]

You're right, if you have a port and it is tagged in a VLAN, if you then add it to a trunk it will become an untagged member of the default VLAN only. At that point you then need to add the trunk to whatever VLAN memberships it requires.

[Anders_35]

Thanks, I thought it sounded a bit weird...

But so does a lot of the other questions. I'm never getting a practice test like this again, it's soooo bogus.

[Matt Hobbs]

If you're clever enough to pick up the mistakes like that you'll pass the exam no problem at all.

Just remember when using spanning-tree to tag all VLANs on your switch to switch links!