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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 15 Configuring VLANs
Configuring Normal-Range VLANs
For more detailed definitions of access and trunk modes and their functions, see Table 15-4 on
page 15-16.
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
page 7-19.
Configuring Normal-Range VLANs
Normal-range VLANs are VLANs with VLAN IDs 1 to 1005. If the switch is in VTP server or
VTP 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.)
In VTP versions 1 and 2, the switch must be in VTP transparent mode when you create extended-range
VLANs (VLANs with IDs from 1006 to 4094), but these VLANs are not saved in the VLAN database.
VTP version 3 supports extended-range VLANs in VTP server and transparent mode. See the
“Configuring Extended-Range VLANs” section on page 15-10.
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. On a Catalyst 3750-X switch, thevlan.dat file is stored in flash memory on the stack master.
Stack members have a vlan.dat file that is consistent with the stack master.
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 Chapter 16, “Configuring
VTP.”
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