Displaying VLAN Information
2900/2950 Series Switch
2900Switch#show vlan | Shows all VLAN status |
2900Switch#show vlan brief | Shows all VLAN status in brief |
2900Switch#show vlan id 2 | Displays information of VLAN 2 only |
2900Switch#show vlan name Marketing | Displays information of VLAN named Marketing only |
Creating Static VLANs
2900 Series Switch
2900Switch#vlan database | Enters VLAN database mode |
2900(vlan)#vlan 2 name Engineering | Creates VLAN 2 and names it Engineering |
2900(vlan)#vlan 3 name Marketing | Creates VLAN 3 and names it Marketing |
2900(vlan)#exit | Applies changes and exits VLAN database mode |
2900# |
2950 Series Switch
2950Switch#config t | Enters global config mode |
2950Switch(config)#vlan 10 | Creates VLAN 10 and enters VLAN config mode for further definitions |
2950Switch(config-vlan)#name Accounting | Assigns a name to a VLAN |
2950Switch(config-vlan)#exit | Moves back to global config mode |
2950Switch(config)#vlan 20 | Creates VLAN 20 and enters VLAN config mode for further definitions |
2950Switch(config-vlan)#name Sales | Assigns a name to a VLAN |
2950Switch(config-vlan)#exit | Moves back to global config mode |
Tip:
For the 2900 series switch, you must apply the changes to the VLAN database for the changes to take effect. You can also use the command apply in the VLAN database, which will apply the changes, but not exit the mode. Using the command to exit out of the VLAN database will not apply the changes to the VLAN database. You must use the command exit to exit the VLAN database and have the changes successfully applied.
Tip:
For the 2950 series switch, the use of the VLAN database is being phased out, in favor of creating VLANs in the manner demonstrated in the preceding command syntax. If you use the vlan database command at the 2950Switch# prompt, the 2950 IOS will tell you this but will still allow you to use commands the same as the 2900 series switch. Get used to this style; it is the method to be used on all future releases of switches.
Assigning Ports to VLANs
2900/2950 Series Switch
2900Switch#config t | |
2900Switch(config)#int fa0/2 | Moves to interface mode |
2900Switch(config-if)#switchport mode access | Sets switchport mode to access |
2900Switch(config-if)#switchport access vlan 2 | Assigns this port to VLAN 2 |
2900Switch(config-if)#int fa0/3 | Moves to interface mode |
2900Switch(config-if)#switchport mode access | Sets switchport mode to access |
2900Switch(config-if)#switchport access vlan 3 | Assigns this port to VLAN 3 |
2900Switch(config-if)#exit | Exits interface mode |
2900Switch(config)# |
Assigning Ports Using the range Command (2950 Switch Only)
2950Switch(config)#int range fa 0/1 – 4 | Enables you to set the same configuration para-meters on multiple ports at the same time. Note that there is a space before and after the hyphen |
2950Switch(config-if-range)#switchport mode access | Sets all ports to access mode |
2950Switch(config-if-range)#switchport access vlan 10 | Assigns all ports to VLAN 10 |
Saving VLAN Configurations
2900/2950 Series Switch
Any command entered in the VLAN database is automatically saved as long as you leave the VLAN database properly with the exit command, and not .
Switch#copy run start | Saves the running-config to NVRAM |
Erasing VLAN Configurations
2900/2950 Series Switch
2900Switch#delete flash:vlan.dat | Removes entire VLAN database from Flash memory
Make sure there is no space between the colon (:) and the characters vlan.dat. You can potentially erase the entire contents of Flash memory with this command if the syntax is not correct |
2900Switch#delete flash: | |
Delete filename [ ]? vlan.dat | Removes entire VLAN database from Flash memory |
Delete flash:vlan.dat? [confirm] | Press the ENTER key |
2900Switch# | |
or | |
2900Switch#config t | |
2900Switch(config)#int fa 0/3 | |
2900Switch(config-if)#no switchport access vlan 3 | Removes port from VLAN 3 and reassigns it to default VLAN 1 |
2900Switch(config-if)#exit | |
2900Switch(config)#exit | |
2900Switch#vlan database | Enters VLAN database mode |
2900(vlan)#no vlan 3 | Removes only VLAN 2 from database |
2900(vlan)#exit | Applies changes and exits VLAN database mode |
Note:
For any series switch, you cannot remove VLAN 1.
Troubleshooting VLANs
2900Switch#show vlan | Displays the complete VLAN database |
2900Switch#show vlan brief | Displays a summary of the VLAN database |
2900Switch#show interfaces | Displays a summary of each interface, including speed and duplex settings |
2900Switch#debug sw-vlan packets | Displays information about VLAN packets a router has received but is not capable of supporting |