VLAN Window

This window appears when you take either of these actions:

You can also click here to launch it.

The window has these tabs:

Begin by selecting a device from the Host Name list. The device that you select determines the VLAN information, the VTP information, and the configuration choices you see in the window.

When you finish adding or modifying options, click OK.

Assign VLANs

This tab identifies:

To change the administrative mode or the VLAN assignments for one or more interfaces:

  1. Select one or more interfaces.
    To select more than one, hold down the Ctrl key and click individual interfaces, or hold down the Shift key and select the first and last interfaces in a range.
  2. Click Modify to display the Modify VLAN Assignment window.
  3. Complete the window.
  4. Click OK to close the window.
    Your changes will appear on the Assign VLANs tab.

Configure Trunks

The columns on this tab vary according to the selected device. The columns have these meanings.

Column Appears for... Meaning
Interface Any selected device The trunk ports on the device.
Administrative Trunking Encapsulation Catalyst 2950 and 3550 only The mode of trucking encapsulation used.
Operational Trunking Encapsulation Catalyst 2950 and 3550 only The trunking mode that each port is operating in.
Allowed VLAN List Any selected device The VLANs that are allowed to use the trunk.
VLAN Pruning Eligibility List Any selected device The VLANs that are eligible for VTP pruning.
Native VLAN Any selected device The native VLAN for the trunk ports.

To change the trunking encapsulation mode, allowed VLAN list, pruning eligibility list, or native VLAN:

  1. Select one or more interfaces.
    To select more than one, hold down the Ctrl key and click individual interfaces, or hold down the Shift key and select the first and last interfaces in a range.
  2. Click Modify to display the Modify Trunk Configuration window.
  3. Complete the window.
  4. Click OK to close the window.
    Your changes will appear on the Configure Trunks tab.

Configure VTP

The read-only fields display information about VTP and the VLAN configuration it maintains: the version of VTP in use, the current configuration revision number, the maximum number of VLANs that you can create on the switch, the number of VLANs that exist on the switch, and the last time the VLAN configuration was modified.

To configure VTP:

  1. From the VTP V2 Mode list, select Enabled to enable version 2.
    By default, Disabled is selected, which means that version 1 mode is selected.
    Each VTP switch automatically detects the capabilities of all the other VTP devices. All VTP switches in the network must support version 2 mode; otherwise, you must configure them to operate with VTP version 1.
    Note: If you are using VTP in a Token Ring environment or configuring a TRBRF or TRCRF VLAN media type, you must set VTP V2 Mode to Enabled. If you are configuring a Token Ring or Token Ring-NET VLAN media type, you must disable VTP V2 mode.
  2. From the VTP Mode Control list, select a mode. This table explains the choices.
    Mode Explanation
    Server A switch in VTP server mode is enabled for VTP and sends advertisements. You can configure VLANs on it. The switch can recover all the VLAN information in the current VTP database from nonvolatile storage after reboot. By default, every switch is a VTP server, which is the recommended mode of operation.
    Client A switch in VTP client mode is enabled for VTP and can send advertisements, but it does not have enough nonvolatile storage to store VLAN configurations. You cannot configure VLANs on it. When a VTP client starts up, it does not transmit VTP advertisements until it receives advertisements to initialize its VLAN database.
    Transparent A switch in VTP transparent mode is locally disabled for VTP, but it does not transmit advertisements or learn from advertisements sent by other devices, and it cannot affect VLAN configurations on other devices in the network. The switch receives VTP advertisements and forwards them on all trunk ports except the one on which the advertisement was received.

    The default is Server.
    If you select Client, you cannot add, modify, or remove VLAN configurations.
    The mode must be Transparent if the selected device is a Catalyst 2950 or 3550 switch on a VLAN whose ID is 1006 to 4094.

  3. From the VTP Pruning Mode list, select Enabled.
    By default, pruning is disabled. When enabled, global pruning occurs for the entire management domain. Pruning restricts flooded traffic to trunk links that the traffic must use to access ports where the traffic is required.
    Note: You can specify the VLANs where pruning is done by using the VLAN Pruning Eligibility section of the Modify Trunk Configuration window.
  4. In the Domain Name field, enter a name that identifies the administrative domain for the switch.
    Note: Do not configure a domain name if all switches are operating as VTP clients; in this case, configuring a domain name makes changing the VLAN configuration for the domain impossible.
    By default, no domain name is defined, but VTP is not active until a name is defined or until it is learned from an advertisement.
    Domain names range from 1 to 32 characters and are case sensitive.
    Note: After the domain name is configured or learned, you cannot reset it to a blank or undefined name.
    If you are configuring the switch for VMPS, make sure this domain name matches the one in the VMPS configuration file.
  5. Optional: In the VTP Password field, enter a password.
    Passwords range from 8 to 64 characters and are case sensitive. By default, no password is defined.
    If you assign a VTP password, it must match the password for the VTP domain of the switch. This password is required for authentication when VTP advertisements reach the switch.
    Note: Catalyst 2900 XL or 3500 XL switches that boot without the correct VTP password reject VTP advertisements until this password is assigned. If you add a switch to a network that uses VTP, the switch learns the VTP domain name after the domain password is assigned.

Configure VLANs

This tab displays information about the VLANs that are associated with the selected device.

If you want to see the device ports in the Front Panel view that belong to a VLAN:

  1. Select the VLAN by selecting a row in the table.
  2. Click Highlight VLAN Port Membership Modes.

The color that outlines the ports in the Front Panel view represents a VLAN mode. Go to VLAN Modes in the legend to see what colors represent the VLAN modes.

The information in the table is updated when you take one of these actions: