Summary Of Acl Actions; Understanding Acl Precedence; Table 7-4 Acl Precedence Groups - Nortel Alteon OS 42C4911 Application Manual

Alteon OS Application Guide

Summary of ACL Actions

Actions determine how the traffic is treated.
Pass or Drop
Re-mark a new DiffServ Code Point (DSCP)
Re-mark the 802.1p field
Set the COS queue

Understanding ACL Precedence

Each ACL has a unique precedence level, based on its number. When an incoming packet
matches the highest precedence ACL, the ACL's configured action takes place. The other
assigned ACLs also are considered, in order of precedence.
ACLs are divided into seven major Precedence Groups, as shown in

Table 7-4 ACL Precedence Groups

Precedence Group
Precedence Group 1
Precedence Group 2
Precedence Group 3
N – Precedence Groups are not related to ACL Groups.
OTE
Each Precedence Group has its own precedence level, such that Precedence Group 2 has a
higher precedence level than Precedence Group 1. Within each Precedence Group, the lowest-
numbered ACL has the lowest precedence level, and the highest-numbered ACL has the high-
est precedence level. However, the other ACLs within the Precedence Group have an unspeci-
fied precedence level, as follows:
ACL 1 = lowest precedence level within Precedence Group 1
ACL 2 = unspecified precedence level within Precedence Group 1
ACL 3 = unspecified precedence level within Precedence Group 1
...
ACL 126 = unspecified precedence level within Precedence Group 1
ACL 127 = unspecified precedence level within Precedence Group 1
ACL 128 = highest precedence level within Precedence Group 1
128 Chapter 7: Quality of Service
The GbESM QoS actions include the following:
ACLs Precedence Level
ACL 1 - ACL 128
ACL 129 - ACL 256
ACL 257 - ACL 384
Table 7-4.
Low
High
42C4911, January 2007