Avaya Cajun P580, User Manual, Page: 668 / 770

25-8 User Guide for the Avaya P580 and P882 Multiservice Switches, v6.0
Chapter 25
However, the priority of the 802.1 tag and Cisco ISL tag take precedence
over the priority of the physical port, so the switch uses the priority of the
physical port only if:
■
No tags are present in the frame
or
■
You have set the physical port to ignore priorities in tags.
For information on how to set a port to ignore priorities in tags, see
“
Setting a Physical Port to Ignore Tag Priority ” later in this chapter.
* Note: 802.1p packets that are received with a tag priority of 0 on a 50-
series layer 2 (non-routing) module, and that must be routed
via the FORE path on an 80-series supervisor, are queued and
transmitted with a priority of 4. This priority change is due to
the conversion from the high-low priority system that 50-series
modules use to the 8-level priority system that 80-series
modules use.
Classifying Traffic by Layer 2 Characteristics
In addition to Cisco ISL tag, 802.1p tag, and physical port priority, the
switch can classify traffic by:
■
Source MAC address
■
Destination MAC address
For information about how to set a priority for a source or destination MAC
address, see “
Setting the Priority of a MAC Address ” later in this chapter.
In addition to these layer 2 characteristics, you can classify bridged IP
traffic by DiffServ code point. For more information on classifying bridged
IP traffic by DiffServ code point, see “
Diffserv ” later in this chapter.
Classifying Traffic by Layer 3 or Layer 4 Characteristics
ACL Rules
You can, alternately, configure the switch to classify traffic by the IP
characteristics of packets, instead of 802.1p tag priority, physical port
priority, or other layer 2 characteristics.
To assign priorities to packets by their IP characteristics, you create a rule in
an access control list (ACL). The rule can:
■
Set an ACL rule priority