Cisco IE 4000, Software Configuration Manual

Page: 278 / 1066

274
Configuring VLANs
VLANs
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
You configure VLANs in vlan global configuration command by entering a VLAN ID. Enter a new VLAN ID to create a
VLAN, or enter an existing VLAN ID to modify that VLAN. You can use the default VLAN configuration ( Table 34 on
page 276 ) or enter multiple commands to configure the VLAN. When you have finished the configuration, you must exit
VLAN configuration mode for the configuration to take effect. To display the VLAN configuration, enter the show vlan
privileged EXEC command.
The configurations of VLAN IDs 1 to 1005 are always saved in the VLAN database (vlan.dat file). If the VTP mode is
transparent, they are also saved in the switch running configuration file. You can enter the
copy running-config
startup-config privileged EXEC command to save the configuration in the startup 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 selected 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 match the VLAN database, the domain name
and VTP mode and configuration for the first 1005 VLANs use the VLAN database information.

In VTP versions 1 and 2, if VTP mode is server, the domain name and VLAN configuration for only the first 1005
VLANs use the VLAN database information. VTP version 3 also supports VLANs 1006 to 4096.
Token Ring VLANs
Although the switch does not support Token Ring connections, a remote device such as a Catalyst 6500 series switch
with Token Ring connections could be managed from one of the supported switches. Switches running VTP Version 2
advertise information about these Token Ring VLANs:

Token Ring TrBRF VLANs