what is port tagging/untagging

[Luis]

My question to you smart ones is; what is port tagging and how does it work?

Ant feedback would be greately appreciated.

Thank You

-Luis

[sysguy]

I will take a shot at this one.

Port tagging is used whenever you want to connect multiple vlans together and don't want to physically connect each vlan by running a cable to every single one.

So you want to connect Vlan A and Vlan B on switch 1, to Vlan A and Vlan B on switch 2. You could run a single cable on one of the ports and "TAG" it instead of having to physically connect each Vlan/switch.

In fewer words, All of your Vlan traffic will go through the tagged port(s) that connect your Vlan's across multiple switches.

[Planet]

I will take a shot at this one.

Port tagging is used whenever you want to connect multiple vlans together and don't want to physically connect each vlan by running a cable to every single one.

So you want to connect Vlan A and Vlan B on switch 1, to Vlan A and Vlan B on switch 2. You could run a single cable on one of the ports and "TAG" it instead of having to physically connect each Vlan/switch.

In fewer words, All of your Vlan traffic will go through the tagged port(s) that connect your Vlan's across multiple switches. never had to do it myself, but that sound reasonable ;)

[davis]

Acceptable, but i believe thats called "trunking"; the packets themselves are "Tagged" with a 802.1q note to tell them which vlan they belong to.

Port tagging could also be referred to as NAT (http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214107,00.html).

Or physical Security on the switch "tagging" the port with a limited number of MAC addresses so users cant being in their home PC or a network storage unit to download data.

Guess we need to know the context on this one :p