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    CAM Hardware Classifiers Overview

    Content-addressable memory (CAM) hardware classifiers are supported on the OC48/STM16, GE-2, ES2 4G, ES2 10G, ES2 10G Uplink, and GE-HDE line modules.Policy Resources Overview lists CAM hardware classifiers and the software classifiers supported for each interface type.

    The OC48/STM16 line module supports 128,000 144-bit CAM entries, and the GE-2 and GE-HDE line modules support 64,000 144-bit CAM entries. The ES2 4G LMs on E120 and E320 routers support 256,000 144-bit CAM entries, and the ES2 10G and ES2 10G Uplink LMs on E120 and E320 routers support 128,000 144-bit CAM entries. For most configurations, each classifier entry in a policy consumes one CAM entry. However, a policy that has only the default classifier consumes no CAM resources.

    In this example, the policy consumes a total of four CAM entries: two entries for clacl1, one for clacl2, and one for the default classifier.

    host1(config)#ip classifier-list clacl1 ip host host tos 1 host1(config)#ip classifier-list clacl1 ip host host tos 2 host1(config)#ip classifier-list clacl2 tcp any any tcp-flags "SYN"host1(config)#ip policy-list policy1 host1(config-policy-list)#classifier-group clacl1 host1(config-policy-list-classifier-group)#forward host1(config-policy-list-classifier-group)#exit host1(config-policy-list)#classifier-group clacl2 host1(config-policy-list-classifier-group)#forward host1(config-policy-list-classifier-group)#exit host1(config-policy-list)#classifier-group * host1(config-policy-list-classifier-group)#filter host1(config-policy-list-classifier-group)#exit host1(config-policy-list)#exit

    A single classifier entry consumes more than one CAM entry when:

    • A classifier entry contains a port range. For example:
      host1(config)#ip classifier-list clacl3 tcp any any range 5 8
    • A classifier entry contains the not keyword. Although this keyword is supported for IP classifier lists, we recommend that you not use it—you can usually achieve the desired behavior without this keyword.
      host1(config)#ip classifier-list clacl4 ip not host any

    In these cases, the actual number of entries that are consumed depends on the configuration.

    Published: 2014-08-14