Reference Guide

Content Addressable Memory | 281
CAM Optimization
CAM optimization is supported on platforms c s
When this command is enabled, if a Policy Map containing classification rules (ACL and/or dscp/
ip-precedence rules) is applied to more than one physical interface on the same port-pipe, only a single
copy of the policy is written (only 1 FP entry will be used). When the command is disabled, the system
behaves as described in this chapter.
Applications for CAM Profiling
LAG Hashing
FTOS includes a CAM profile and microcode that treats MPLS packets as non-IP packets. Normally,
switching and LAG hashing is based on source and destination MAC addresses. Alternatively, you can
base LAG hashing for MPLS packets on source and destination IP addresses. This type of hashing is
allowed for MPLS packets with 5 labels or less.
MPLS packets are treated as follows:
• When MPLS IP packets are received, FTOS looks up to 5 labels deep for the IP header.
• When an IP header is present, hashing is based on IP 3 tuple (source IP address, destination IP address,
and IP protocol).
• If an IP header is not found after the 5th label, hashing is based on the MPLS labels.
• If the packet has more than 5 MPLS labels, hashing is based on the source and destination MAC
address.
To enable this type of hashing, use the default CAM profile with the microcode
lag-hash-mpls.
LAG Hashing based on Bidirectional Flow
To hash LAG packets such that both directions of a bidirectional flow (for example, VoIP or P2P file
sharing) are mapped to the same output link in the LAG bundle, use the default CAM profile with the
microcode lag-hash-align.
CAM profile for the VLAN ACL group feature
IPv4Flow sub-partitions are supported on platform e
t
only.
To optimize for the VLAN ACL Group feature, which permits group VLANs for the IP egress ACL, use
the CAM profile
ipv4-egacl-16k with the default microcode.
Note: Do not use this CAM profile for Layer 2 egress ACLs.