Static Virtual LANs


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NOTE: All commands previously in the Summary of commands table are indexed under the entry Command syntax.


General steps for using VLANs

VLANs enable grouping users by logical function instead of physical location. They make managing bandwidth usage within networks possible by:

  • Allowing grouping of high-bandwidth users on low-traffic segments

  • Organizing users from different LAN segments according to their need for common resources and individual protocols

  • Improving traffic control at the edge of networks by separating traffic of different protocol types

  • Enhancing network security by creating subnets to control in-band access to specific network resources

This chapter describes static VLANs configured for port-based or protocol-based operation.

Static VLANs are configured with a name, VLAN ID number (VID), and port members. For dynamic VLANs, 802.1Q compatibility enables you to assign each switch port to multiple VLANs.

Some recommended steps to take for using VLANs:

  1. Plan your VLAN strategy and create a map of the logical topology. Include consideration for the interaction between VLANs and other features such as Spanning Tree Protocol, port trunking, and IGMP. If you plan on using dynamic VLANs, include the port configuration planning necessary to support this feature.

    By default, the switches covered in this guide are 802.1Q VLAN-enabled, allow for up to 256 static VLANs, and 2048 total static and dynamic VLANs.

  2. Configure at least one VLAN and the default VLAN.

  3. Assign the desired switch ports to the new VLANs.

  4. If you are managing VLANs with SNMP in an IP network, the VLAN through which you are managing the switch must have an IP address.

Configuring VLANs

The Menu interface enables configuration and display of port-based VLANs only. The CLI configures and displays port-based and protocol-based VLANs.

In the factory default state, the switch is enabled for up to 256 VLANs, all ports belong to the default primary VLAN and are in the same broadcast/multicast domain. You can reconfigure the switch to support up to 2048 VLANs, with up to 4094 VIDs, by adding new VLAN names and VIDs, and then assigning one or more ports to each VLAN.

Per-port static VLAN configuration options

Options available to assign individual ports to a static VLAN are GVRP, if configured, which affects these options and the VLAN behavior on the switch.

Comparing per-port VLAN options with and without GVRP

Comparing per-port VLAN options with and without GVRP

Per-port VLAN configuration options

Parameter Effect on port participation in designated VLAN
Tagged Allows the port to join multiple VLANs.
Untagged
  • Allows VLAN connection to a device that is configured for an untagged VLAN instead of a tagged VLAN.

  • A port can be an untagged member of only one port-based VLAN.

  • A port can be an untagged member of only one protocol-based VLAN for any given protocol type.

For example, if the switch is configured with the default VLAN plus three protocol-based VLANs that include IPX, then port 1 can be an untagged member of the default VLAN and one of the protocol-based VLANS.

No or Auto No:

When the switch is not GVRP-enabled; prevents the port from joining that VLAN.Auto: When GVRP is enabled on the switch; allows the port to dynamically join any advertised VLAN that has the same VID.

Forbid Prevents the port from joining the VLAN, even if GVRP is enabled on the switch.