Business Policy Switch User Guide

280 Chapter 4 Policy-enabled networks
208700-B
Each group of filters is associated with actions that are executed when the packet
matches the filters in the group. The filter group and the associated actions,
meters, and interface groups are referenced by a policy, which dictates the overall
traffic treatment.
Filters are associated with an interface group, action, and metering through a
policy. There are two levels of precedence that both work from the lowest order to
the highest:
order of filters in a filter group
order of policies
Layer 2 filters
There are 14 available layer 2 filters in the BPS 2000. The layer 2 filters are used
to classify traffic based on the following criteria:
Layer 2 information, including VLAN ID, IEEE 802.1p priority, and
etherType
Layer 3 information, including DSCP and IP protocol such as TCP/UDP
Layer 4 information, including TCP/UDP port ranges
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.
Note: Among policies, any policy with a Layer 2 filter group must have
a lower precedence (higher order) than any policy with an IP filter group.
Note: If a layer 2 filter specifies layer 3 or layer 4 information, that filter
must match IP traffic only.