Nortel Networks 2300 manual 802.1Q Tagging, Tunnel Affinity

Configuring and Managing Ports and VLANs 91

802.1Q Tagging

The tagging capabilities of the WSS are very flexible. You can assign 802.1Q tag values on a per-VLAN, per-port basis. The same VLAN can have different tag values on different ports. In addition, the same tag value can be used by different VLANs but on different network ports.

If you use a tag value, Nortel recommends that you use the same value as the VLAN number. WSS Software does not require the VLAN number and tag value to be the same, but some other vendors’ devices do.

Note. Do not assign the same VLAN multiple times using different tag values to the same network port. Although WSS Software does not prohibit you from doing so, the configuration is not supported.

Tunnel Affinity

WSS switches configured as a Mobility Domain allow users to roam seamlessly across AP access ports and even across WSSs. Although a switch that is not a member of a user’s VLAN cannot directly forward traffic for the user, the switch can tunnel the traffic to another WSS switch that is a member of the user’s VLAN.

If the WSS that is not in the user’s VLAN has a choice of more than one other WSS switch through which to tunnel the user’s traffic, the switch selects the other switch based on an affinity value. This is a numeric value that each WSS switch within a Mobility Domain advertises, for each of its VLANs, to all other switches in the Mobility Domain. A switch outside the user’s VLAN selects the other operational switch that has the highest affinity value for the user’s VLAN to forward traffic for the user.

If more than one WSS switch has the highest affinity value, WSS Software randomly selects one of the switches for the tunnel.

Nortel WLAN Security Switch 2300 Series Configuration Guide