3Com 9000 manual Managing Virtual LANs

Managing Virtual LANs 47

■Layer 3 address — On Layer 3 modules, the network or subnetwork address that is associated with a network-based IP VLAN.

■Port membership — The bridge ports that you assign to be part of the VLAN. If you have created trunks, you must specify the anchor port (lowest-numbered) port in the trunk when you define the VLAN. All bridge ports are initially part of the default VLAN on each module.

■VLAN name —The name that you assign to the VLAN. It can contain up to 32 ASCII characters. If the name includes spaces, enclose the name in quotation marks. The default VLAN uses the name Default.

■Ingress and egress rules — Ingress rules determine the VLAN to which an incoming frame belongs. If it cannot be assigned to any VLAN, it is assigned to the null VLAN, which contains no ports and has no associated address table in allClosed mode. Egress rules determine whether the frame is forwarded, flooded, or filtered, as well as the tag status of the transmitted frame.

Procedural Guidelines Follow these procedural guidelines to configure VLANs on the modules in your system:

1Use the EME to connect to each Layer 2 and Layer 3 switching module individually and configure the VLAN mode and VLANs for each module.

2On each switching module, select the VLAN mode of allOpen or allClosed.

3On each switching module, create the appropriate number of VLANs for your configuration. For each VLAN definition:

a Select a VID for the VLAN and provide information based on the type of VLAN: port-based information for Layer 2 modules; port-based, protocol-based, and network-based information for Layer 3 modules.

b Include the appropriate front-panel ports. Tag the front-panel ports if you need to (that is, if the ports overlap with another VLAN and tagging is the only distinguishing characteristic). Remember that if you tag a port, the attached device must support IEEE 802.1Q tagging. If you are configuring a Layer 3 module that serves as a router, your VLAN may or may not include front-panel ports.

c Include the backplane port of the switching module in the VLAN definition unless the VLAN traffic is limited to that switching module only and will not pass through the switch fabric module. If the switching module supports two backplane ports (and resides in a slot that supports two switch fabric module ports), you typically configure