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12-4
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 12 Configuring VLANs
Configuring Normal-Range VLANs
For more detailed definitions of the modes and their functions, see
.
When a port belongs to a VLAN, the switch learns and manages the addresses associated with the port
on a per-VLAN basis. For more information, see the
“Managing the MAC Address Table” section on
Configuring Normal-Range VLANs
Normal-range VLANs are VLANs with VLAN IDs 1 to 1005. If the switch is in VTP server or
transparent mode, you can add, modify or remove configurations for VLANs 2 to 1001 in the VLAN
database. (VLAN IDs 1 and 1002 to 1005 are automatically created and cannot be removed.)
Note
When the switch is in VTP transparent mode, you can also create extended-range VLANs (VLANs with
IDs from 1006 to 4094), but these VLANs are not saved in the VLAN database. See the
Extended-Range VLANs” section on page 12-12
Configurations for VLAN IDs 1 to 1005 are written to the file vlan.dat (VLAN database), and you can
display them by entering the show vlan privileged EXEC command. The vlan.dat file is stored in Flash
memory.
Caution
You can cause inconsistency in the VLAN database if you attempt to manually delete the vlan.dat file.
If you want to modify the VLAN configuration, use the commands described in these sections and in the
command reference for this release. To change the VTP configuration, see
You use the interface configuration mode to define the port membership mode and to add and remove
ports from VLANs. The results of these commands are written to the running-configuration file, and you
can display the file by entering the show running-config privileged EXEC command.
You can set these parameters when you create a new normal-range VLAN or modify an existing VLAN
in the VLAN database:
•
VLAN ID
•
VLAN name
•
VLAN type (Ethernet, Fiber Distributed Data Interface [FDDI], FDDI network entity title [NET],
TrBRF, or TrCRF, Token Ring, Token Ring-Net)
•
VLAN state (active or suspended)
•
Maximum transmission unit (MTU) for the VLAN
•
Security Association Identifier (SAID)
•
Bridge identification number for TrBRF VLANs
•
Ring number for FDDI and TrCRF VLANs
•
Parent VLAN number for TrCRF VLANs
•
Spanning Tree Protocol (STP) type for TrCRF VLANs
•
VLAN number to use when translating from one VLAN type to another