Avaya P880 Switch User Manual


 
5-12
Chapter 5
Cajun P550/P880/P882 Switch User Guide
Assigning VLANs to a Port and Associated Issues
There are two ways to assign VLANs to ports on the P550/P880/
P882 switch. The first, and recommended way, is to assign the VLAN
to a port under the ‘Module & Ports / Switch Ports’ menu on the
web agent. You configure the ‘Port VLAN’ to the VLAN desired for
the individual port (or entire module if configuring that way).
Assigning the VLAN via this route will enable the port(s) to receive
information for the assigned VLAN and more importantly, this
causes all untagged frames arriving on this port to be assigned to the
specified VLAN. The port will still assign incoming tagged packets to
the VLAN indicated by the tag.
In the current release of software, a non-trunk port only supports a
single VLAN per port. Multiple VLANs per port is NOT
recommended and can have adverse effects on network
performance.
The second way is to assign the VLAN to a port is to use the
following CLI command in Priv/Configure mode:
> set port vlan
By selecting the VLAN name, you can bind the selected VLAN to
additional ports. When binding VLANs via this route, the port is part
of the flooding domain of the selected VLAN. This is an alternative
to using the binding types “bind to all” and “bind to receive”, that
allows you to add a port to a subset of VLANs in the switch. This
configuration should only be used under special circumstances and
with the assistance of customer support as undesirable results may
occur (e.g. destination unknown unicast storms).
See Chapter 4, “Using VLANs, Spanning Tree, Hunt Groups, and
VTP Snooping”, for a description of the parameters that will be
displayed when viewing VLAN information via the http
management interface.
Although this method of adding VLANs to a port could be thought
to support the request for multiple VLANs per port (also referred to
as overlapping VLANs), it is NOT recommended on clear ports due
to the impact it has on the network. The impact is that destination
unknown unicast packets is flooded on the VLAN in which the
source host is located. This causes all ports assigned to this VLAN to
receive the destination unknown unicast. If enough of these
destination unknown unicast packets are being sent it could have a
major impact on the network.