Chapter 13
Configuring VLANs
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 (including extended-range VLAN configuration
information) in the startup configuration file and reboot the switch, the switch configuration is
determined as follows:
•
•
•
•
•
Caution
If the startup configuration file contains extended-range VLAN configuration, this information will be
lost when the system boots up.
78-11380-04
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 match the VLAN database,
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 the switch is running IOS release 12.1(9)EA1 or later and you use an older startup configuration
file to boot up the switch, the configuration file does not contain VTP or VLAN information, and
the switch uses the VLAN database configurations.
If the switch is running an IOS release earlier than 12.1(9)EA1 and you use a startup configuration
file from IOS release 12.1(9)EA1 or later to boot up the switch, the image on the switch does not
recognize the VLAN and VTP configurations in the startup configuration file, so the switch uses the
VLAN database configuration.
Catalyst 2950 Desktop Switch Software Configuration Guide
Configuring Normal-Range VLANs
13-9