Chapter 19: Access Control List Configuration Guide

ACL Basics

An ACL consists of one or more rules describing a particular type of IP or IPX traffic. ACLs can be simple, consisting of only one rule, or complicated with many rules. Each rule tells the SSR to either permit or deny packets that match selection criteria specified in the rule.

Each ACL is identified by a name. The name can be a meaningful string, such as denyftp or noweb or it can be a number such as 100 or 101.

For example, the following ACL has a rule that permits all IP packets from subnet 10.2.0.0/16 to go through the SSR:

acl 101 permit ip 10.2.0.0/16

Defining Selection Criteria in ACL Rules

Selection criteria in the rule describe characteristics about a packet. In the example above, the selection criteria are IP packets from 10.2.0.0/16.

The selection criteria you can specify in an ACL rule depends on the type of ACL you are creating. For IP, TCP, and UDP ACLs, the following selection criteria can be specified:

Source IP address

Destination IP address

Source port number

Destination port number

Type of Service (TOS)

The accounting keyword specifies that LFAP accounting information about the flows that match the ‘permit’ rule are sent to the configured Flow Accounting Server (FAS). See Chapter 24, “LFAP Configuration Guide” for more information.

For IPX ACLs, the following selection criteria can be specified:

Source network address

Destination network address

Source IPX socket

Destination IPX socket

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Cabletron Systems 9032578-05 manual ACL Basics, Defining Selection Criteria in ACL Rules