3Com 3500 manual Virtual Lans Vlans

346CHAPTER 14: VIRTUAL LANS (VLANS)

■You must specify a VID in the range from 2 through 4094. You can no longer define a VLAN other than the default VLAN with a VID of 1. VID 1 is reserved for the default VLAN only as of Release 3.0.0. (As of Release 3.0.0, the default VLAN always uses the name Default and the protocol type unspecified.) If you delete the default VLAN, you can redefine it with VID 1 only.

■You cannot delete a VLAN that has a routing interface associated with it.

■If you plan to use the trunking feature or the MPLA feature, define the appropriate trunks before you define your VLANs. See Chapter 11 for more information.

■If you plan for your VLAN to include trunk ports, specify the anchor port (lowest-numbered port) that is associated with the trunk. For example, if ports 1 through 3 are associated with a trunk, specify 1 to define the VLAN to include all of the physical ports in the trunk (ports 1 through 3). If you have not defined trunks, specify one or more port numbers, or all to assign all ports to the VLAN interface.

■If a port is shared by another VLAN, verify that if tagging is the only distinguishing characteristic between the VLANs, the specified tag type is not in conflict with the port’s tag type in another VLAN (that is, there is only one port that is tagged none).

■Do not use this command if you want GVRP to dynamically create IEEE 802.1Q port-based VLANs. Instead, explicitly enable the GVRP state for the participating ports and enable the GVRP state for the entire system. To set the per-port GVRP state, use the bridge port gvrpState. (See Chapter 10.) To set the bridge-wide GVRP state, use the bridge gvrpState command. (See Chapter 9.)

■Whether you are bridging or routing, you can select more than one protocol suite per VLAN and specify one protocol at each of the prompts. Use the protocol type of unspecified to create a port-based VLAN.

■The IPX protocol type IPX-802.2-SNAPis available for both the CoreBuilder 3500 system and the CoreBuilder 9000 Layer 3 switching modules.

■For the CoreBuilder 9000, keep the following considerations in mind:

■When you define a VLAN on a switching module (and other switching modules in the system also define this VLAN), you must define the VLAN on both the switching module and on the switch fabric module.