9-18
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 9 Creating and Maintaining VLANs
VLANs in the VTP Database
This example shows how to add Ethernet VLAN 20 to the VLAN database and name it test20:
Switch# vlan database
Switch(vlan)# vlan 20 name test20
Switch(vlan)# exit
APPLY completed.
Exiting....
Switch# show vlan name test20
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
20 test20 active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
20 enet 100020 1500 - - - - - 0 0
Modifying an Ethernet VLAN
Beginning in privileged EXEC mode, follow these steps to modify an Ethernet VLAN:
To return the VLAN to the default MTU setting, use the no vlan vlan-id mtu VLAN configuration
command.
This example shows how to verify a VLAN configuration:
Switch# show vlan id 20
VLAN Name Status Ports
show vlan---- -------------------------------- --------- -------------------------------
20 VLAN0020 active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
20 enet 100020 1500 - - - - - 0 0
Deleting a VLAN from the Database
When you delete a VLAN from a switch that is in VTP server mode, the VLAN is removed from all
switches in the VTP domain. When you delete a VLAN from a switch that is in VTP transparent mode,
the VLAN is deleted only on that specific switch.
You cannot delete the default VLANs for the different media types: Ethernet VLAN 1 and FDDI or
Token Ring VLANs 1002 to 1005.
Command
Purpose
Step 1
vlan database
Enter VLAN configuration mode.
Step 2
vlan vlan-id mtu mtu-size
Identify the VLAN, and change the MTU size.
Step 3
exit
Update the VLAN database, propagate it throughout the administrative
domain, and return to privileged EXEC mode.
Step 4
show vlan id vlan-id
or
show vlan
Verify your entries.