Lessons · Network switches · reading the VLAN table

Reading the VLAN table

`show vlan brief` lists every VLAN with its number, its name, and every access port in it.

Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.

What it is for

It answers the two questions you will actually be asked: does this VLAN exist, and is this desk in it. One screen, both answers.

How to think about it

Read the Ports column, not the names. A VLAN with a perfect name and no ports is doing nothing, and that is the most common configuration mistake there is.

Worked example

enable

The # prompt.

configure terminal

Into configuration mode.

vlan 30

Something to look at.

name SALES

Named.

exit

Out of the VLAN.

interface gi0/2

One port.

switchport mode access

Access.

switchport access vlan 30

In VLAN 30.

end

Out.

show vlan brief

30 SALES active Gi0/2. The port is on the line, so the VLAN is really in use.

Your turn

List every VLAN and the ports in it.

show vlan

The trap

Looking for a trunk port in this table. Trunks are not in one VLAN, so they do not appear against any of them. `show interfaces status` shows those.

Practise reading the VLAN table on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.