What Is A Secondary Vlan - Alcatel OmniSwitch 6800 Series Network Configuration Manual

Assigning Ports to VLANs

What is a Secondary VLAN?

All mobile ports start out with a configured default VLAN assignment. When mobile port traffic matches
VLAN criteria, the port is assigned to that VLAN. Secondary VLANs are any VLAN a port is subse-
quently assigned to that is not the configured default VLAN for that port.
A mobile port can obtain more than one secondary VLAN assignment under the following conditions:
Mobile port receives untagged frames that contain informatiion that matches rules on more than one
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VLAN. For example, if a mobile port receives IP and IPX frames and their is an IP protocol rule on
VLAN 10 and an IPX protocol rule on VLAN 20, the mobile port is dynamically assigned to both
VLANs. VLANs 10 and 20 become secondary VLAN assignments for the mobile port.
Mobile port receives 802.1Q tagged frames that contain a VLAN ID that matches a VLAN that has
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VLAN mobile tagging enabled. For example, if a mobile port receives frames tagged for VLAN 10, 20
and 30 and these VLANs have mobile tagging enabled, the mobile port is dynamically assigned to all
three VLANs. VLANs 10, 20, and 30 become secondary VLAN assignments for the mobile port.
VLAN Management software on each switch tracks VPAs. When a mobile port link is disabled and then
enabled, all secondary VLAN assignments for that port are automatically dropped and the port's original
configured default VLAN assignment is restored. Switch ports are disabled when a device is disconnected
from the port, a configuration change is made to disable the port, or switch power is turned off.
To view current VPA information for the switch, use the
VLAN associations are identified with a value of mobile in the type field. For more information, see
"Verifying VLAN Port Associations and Mobile Port Properties" on page
OmniSwitch 6800 Series Network Configuration Guide
Understanding Mobile Port Properties
show vlan port command. Dynamic secondary
6-19.
November 2004 page 6-13