Click on the windows logo in Windows 7. Click in the search box and type “cmd”, which is short for “command prompt.” Hit “Enter” and another screen will open. Type the command “telnet x.x.x.x” (without quotes), where “x.x.x.x” is the Internet Protocol (IP) address of the switch that you are connecting to. Enter your user name and password when prompted. The output should be the name of your switch and a blinking cursor waiting to accept commands.
Locate the port in question. Type “show interface description” (without quotes) and hit the “Enter” key. This should display a list of all possible ports on the switch, ordered by type and then by number. Scan the list to locate the port. As an example, say you have the interface “GigabitEthernet0/1.”
Display the configuration for this port by typing “show run interface GigabitEthernet0/1.” The output will indicate a mode. If the mode is “Access” then it will list only one VLAN. If the mode is “Trunk” then there will be a list of VLANs separated by commas or dashes. A dash indicates that all the VLANS within that range are included.
Verify the VLAN and ports by typing the command “show vlan id x,” where “x” is the number of the VLAN. This shows if the VLAN is active and what ports are using the VLAN. This only works to verify one VLAN at a time; there is no command to verify a range of VLAN numbers all at the same time.
Verify the trunk ports. There is a special command to verify what VLANs are allowed on trunk ports. Type the command “show interface trunk” to see what ports are in the list. The port number is listed on the left of the output followed by all of the VLANs that are traveling across that port. This is a fail-safe command because some configurations do not allow you to see the VLANs configured on the trunk. This is a Cisco test question that will earn you big points if you can remember it.