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Catalyst 2940 Switch Software Configuration Guide
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Chapter13 Configuring VLANs
Configuring Normal-Range VLANs

VLAN Configuration in config-vlan Mode

To access config-vlan mode, enter the vlan global configuration command with a VLAN ID. Enter a new
VLAN ID to create a VLAN or with an existing VLAN ID to modify the VLAN. You can use the default
VLAN configuration (Table13-2) or enter multiple commands to configure the VLAN. For more
information about commands available in this mode, refer to the vlan global configuration com mand
description in the command reference for this release. When you have finished the configuration, you
must exit config-vlan mode for the configuration to take effect. To display the VLAN configuration,
enter the show vlan privileged EXEC command.

VLAN Configuration in VLAN Configuration Mode

To access VLAN configuration mode, enter the vlan database privileged EXEC command. Then enter
the vlan command with a new VLAN ID to create a VLAN or with an existing VLAN ID to modify the
VLAN. You can use the default VLAN configuration (Tabl e 13-2 ) or enter multiple commands to
configure the VLAN. For more information about keywords available in this mode, refer to the vlan
VLAN configuration command description in the command reference for this release. When you have
finished the configuration, you must enter apply or exit for the configuration to take effect. When you
enter the exit command, it applies all commands and updates the VLAN database. VTP messages are
sent to other switches in the VTP domain, and the privileged EXEC mode p rom pt a ppea rs .
Saving VLAN Configuration
The configurations of VLAN IDs 1 to 1005 are always saved in the VLAN database (vlan.dat file). If
VTP mode is transparent, they are also saved in the switch running configuration file and you can enter
the copy running-config startup-config privileged EXEC command to save the configuration in the
startup configuration file. You can use the show running-config vlan privileged EXEC command to
display the switch running configuration file. To display the VLAN configuration, enter the show vlan
privileged EXEC command.
When you save VLAN and VTP information in the startup configuration file and reboot the switch, the
switch configuration is determined as follows:
•If the VTP mode is transparent in the startup configuration, and the VLAN database and the VTP
domain name from the VLAN database matches that in the startup configuration file, the VLAN
database is ignored (cleared), and the VTP and VLAN configurations in the startup configuration
file are used. The VLAN database revision number remains unchanged in the VLAN database.
•If the VTP mode or domain name in the startup configuration does not mat ch t he V LAN datab as e,
the domain name and VTP mode and configuration for the first 1005 VLANs use the VLAN
database information.
•If VTP mode is server, the domain name and VLAN configuration for the first 1005 VLANs use the
VLAN database information
•If you use an older startup configuration file to boot up the switch, the c onfigura tion file does not
contain VTP or VLAN information, and the switch uses the V LAN dat aba se c onfiguratio ns.