Nortel business policy switch 2000, Руководство пользователя

Страница: 293 / 412

Chapter 4 Policy-enabled networks 293
Using the Business Policy Switch 2000 Version 2.0
Beginning with software version 2.0, you can filter multiple VLANs with a single
layer 2 filter. You can filter up to 32 VLANs with a single layer 2 filter.
Layer 2 classifiers can be associated with the following actions:
• Drop matching packets.
• Change DSCP of matching IP packets. If you request changing the DSCP for
non-IP traffic, the request will be ignored.
• Change IEEE 802.1p and drop precedence of matching packets.
If a layer 2 filter is installed on a trusted port, then it cannot change the DSCP of
the matching IP traffic or the IEEE 802.1p for all types of traffic. If a layer 2 filter
is installed on an untrusted port, then the associated action must change the DSCP
(if matching IP traffic), IEEE 802.1p, and drop precedence of all matching traffic.
If a layer 2 filter is installed on an unrestricted port, you can specify an action to
change or ignore either the DSCP (if matching IP traffic), IEEE 802.1p, and drop
precedence of the matching traffic.
Refer to Table 57 and Table 58 for more information on layer 2 traffic, either IP or
non-IP, and trusted, untrusted, or unrestricted ports.
IP filters
IP filters are used to classify IP traffic based on the following criteria:
• Layer 3 information, including IP source and subnet addresses, IP destination
and subnet addresses, DSCP, and IP protocols such as TCP/UDP
• Layer 4 information, including TCP/UDP port numbers (port ranges are not
supported by layer 3 filters)
Note: If a layer 2 filter specifies layer 3 or layer 4 information, that filter
must match IP traffic only.