Allied Telesis C613-02013-00 manual Static and dynamic VLANs, Creating VLANs Without VLAN Tags

Layer 2 Switching 37

Static and dynamic VLANs

All VLANs created by the user on the command line are static VLANs. The default VLAN is also a static VLAN.

Dynamic VLANs are created by GVRP, a GARP application whose purpose is to propagate VLAN information between VLAN aware switches. These dynamic VLANs are entitled gvrpxxx, where xxx is the VLAN’s VLAN identifier. Dynamic VLANs will only be created if GVRP is enabled on the switch. GVRP is disabled by default.

All static VLANs except for the default VLAN can be destroyed by the user. Dynamic VLANs cannot be directly destroyed by the user, but may be destroyed according to the operations of GVRP by using the RESET GARP command or by disabling the GVRP instance.

The user can add, delete or modify ports belonging to any static VLAN. The user cannot add, delete or modify ports belonging to a dynamic VLAN. Dynamic VLANs created by GVRP only include tagged ports.

A port must belong to at least one static VLAN.

Creating VLANs Without VLAN Tags

VLANs that do not send any VLAN-tagged frames are logical groupings of ports. Any devices connected to the member ports share a common broadcast domain. The switch only forwards the traffic in a VLAN to the member ports.

Before any VLAN configuration has been entered, the switch has one default VLAN, which is initially configured to send untagged packets over all its member ports. More such VLANs can be created on the switch at any time. Each new VLAN is created with a VLAN name that is unique in the switch, and a VLAN Identifier (VID) that uniquely identifies the VLAN on the physical LAN. The default VLAN always has a VID of 1.

VLANs are created with the commands:

CREATE VLAN=vlanname VID=2..4094

The VLAN parameter specifies a unique name for the VLAN. This name can be more meaningful than the VID, to make administration easier. The VLAN name is only used within the switch; it is not transmitted to other VLAN-aware devices, or used in the Forwarding Process or kept in the Forwarding Database.

The VID parameter specifies a unique VLAN IDentifier for the VLAN. If VLAN-tagged ports are added to this VLAN, the specified VID is used in the VID field of the tag in outgoing frames. If VLAN-untagged ports are added to this VLAN, the specified VID only acts as an identifier for the VLAN in the Forwarding Database. The default port based VLAN has a VID of 1.

By default, all the ports on the switch belong to the default VLAN, except the mirror port if there is one configured. Any port can be added untagged to another VLAN, and is then automatically removed from the default VLAN. A port can only be untagged for one VLAN. A port can only be added to the default VLAN as an untagged port if it is not an untagged port for another VLAN.

Untagged ports are added to VLANs using the command:

ADD VLAN={vlanname1..4094} PORT={port-listALL}

Rapier Switch Software Release 2.2.1 C613-02013-00 Rev A