Avaya P580 - Manual (Page 654)

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Chapter
Avaya P550R, P580, P880, and P882 Multiservice Switch User Guide, v5.3.1
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” on
page 14.
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” on page 16.
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” on page 10.
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
■
Use the DiffServ code point
■
Mask the three least significant bits of the DSCP. The switch
recognizes the remaining bits as the IP precedence field.