# Classifier Control Lists Overview

Classifier control lists (CLACLs) specify the criteria by which the router defines a packet flow. Table 3 lists the criteria that you can use to create CLACLs for different types of traffic flows.

Table 3: CLACL Criteria

Type of CLACL | Criteria
--- | ---
ATM | CLP Color Traffic class User packet class
Frame Relay | Color Mark discard eligibility (DE) bit Traffic class User packet class
GRE | Color Traffic class Type-of-service (ToS) byte User packet class
IP | Color Destination IP address Destination port Destination route class Internet Control Message Protocol (ICMP) Internet Gateway Management Protocol (IGMP) IP flags IP fragmentation offset Locally destined traffic Protocol Source IP address Source port Source route class Transmission Control Protocol (TCP) Traffic class Type-of-service (ToS) byte User Datagram Protocol (UDP) User packet class
IPv6 | Color Destination IPv6 address Destination port Destination route class Internet Control Message Protocol version 6 (ICMPv6) IPv6 traffic class Locally destined traffic Multicast Listener Discovery (MLD) Next header Source IPv6 address Source port Source route class Traffic class Transmission Control Protocol (TCP) User Datagram Protocol (UDP) User packet class
L2TP | Color Traffic class User packet class
MPLS | Color Mark experimental (EXP) bit Traffic class User packet class
VLAN | Color Traffic class User packet class User priority

You configure CLACLs with a name and then values to match in the IP datagram header. A CLACL does not include an action: actions take place when a match is included in a policy list.

| Note: Do not use the asterisk (*) for the name of a classifier list. The asterisk is used as a wildcard for the classifier-group command. If you do not specify one of the frame-relay, gre-tunnel, ip, ipv6, l2tp, mpls, or vlan keywords, the router creates an IP classifier list. This version of the command has been deprecated and may be removed in a future release.

#### Related Documentation

- For information about the hardware and software CLACLs that are supported for each interface type, see Policy Resources Overview.
- For information about monitoring Classifier Lists, see Monitoring Policy Management Overview.