Understanding Mobile Port Properties; What Is A Configured Default Vlan - Alcatel OmniSwitch 6800 Series Network Configuration Manual

Understanding Mobile Port Properties

When BPDU ignore is enabled and the mobile port receives a BPDU, the following occurs:
The port retains its mobile status and remains eligible for dynamic VLAN assignment.
•
The port is not included in the Spanning Tree algorithm.
•
Note. Enabling BPDU ignore is not recommended. In specific cases where it is required, such as connect-
ing legacy networks to mobile port networks, make sure that ignoring BPDU on a mobile port will not
cause network loops to go undetected. Connectivity problems could also result if a mobile BPDU port
dynamically moves out of its configured default VLAN where it provides traffic flow to/from the network.
The following command enables mobility and BPDU ignore on port 8 of slot 3:
-> vlan port mobile 3/8 BPDU ignore enable
Enabling mobility on an active port that sends or receives BPDU (e.g. ports that connect two switches and
Spanning Tree is enabled on both the ports and their assigned VLANs) is not allowed. If mobility is
required on this type of port, enable mobility and the BPDU ignore parameter when the port is not active.
Understanding Mobile Port Properties
Dynamic assignment of mobile ports occurs without user intervention when mobile port traffic matches
VLAN criteria. When ports are dynamically assigned, however, the following configurable mobile port
properties affect how a port uses its configured default VLAN and how long it retains a VLAN port associ-
ation (VPA):
Mobile Port Property If enabled
Default VLAN
Restore default VLAN Port does not retain a dynamic VPA when
The effects of enabling or disabling mobile port properties are described through the following diagrams:
How Mobile Port Traffic that Does Not Match any VLAN Rules is Classified on
•
How Mobile Port VLAN Assignments Age on
•

What is a Configured Default VLAN?

Every switch port, mobile or non-mobile, has a configured default VLAN. Initially, this is VLAN 1 for all
ports, but is configurable using the
Assigning Ports to VLANs" on page
To view current VPA information for the switch, use the
VLAN associations are identified with a value of default in the type field. For more information, see
"Verifying VLAN Port Associations and Mobile Port Properties" on page
page 6-12
Port traffic that does not match any VLAN
rules configured on the switch is flooded
on the port's configured default VLAN.
the traffic that triggered the assignment
ages out of the switch MAC address table
(forwarding database).
vlan port default
6-4.
OmniSwitch 6800 Series Network Configuration Guide
If disabled
Port traffic that does not match any
VLAN rules is discarded.
Port retains a dynamic VPA when
the qualifying traffic ages out of the
switch MAC address table.
page 6-15.
command. For more information, see
show vlan port command. Configured default
6-19.
Assigning Ports to VLANs
page 6-14.
"Statically
November 2004