Reference Guide

220 | Content Addressable Memory
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There is a default microcode, and several other microcodes are available, so that you can adjust packet
handling according to your application. Specifying a microcode is mandatory when selecting a CAM
profile (though you are not required to change it).
Boot Behavior
The profile and microcode loaded on the primary RPM determines the profile and microcode that is
required on all other chassis components and is called the “chassis profile.” A profile mismatch condition
exists if either the CAM profile or the microcode does not match.
The following points describe line
card boot behavior when the line card profile does not match the chassis profile.
• A microcode mismatch constitutes a profile mismatch.
• When the line card profile and chassis profile are of the same type (single-CAM or dual-CAM), but
their CAM profiles do not match, the line card must load a new profile and therefore takes longer to
come online.
• If you insert a single-CAM line card into a chassis with a dual-CAM profile, the system displays
Message 1. The line card boots with the default (single-CAM) profile and remains in a problem state
(Figure 10-1). The line card cannot forward traffic in a problem state.
Note: Not all CAM profiles and microcodes are available for all systems. Refer to the Command Line
Interface Reference Guide for details regarding available profiles for each system.
Table 10-3. Microcode Descriptions
Microcode Description
default Distributes CAM space for a typical deployment
lag-hash-align
For applications that require the same hashing for bi-directional traffic (for
example, VoIP call or P2P file sharing). For port-channels, this microcode
maps both directions of a bi-directional flow to the same output link.
lag-hash-mpls For hashing based on MPLS labels (up to five labels deep). With the default microcode, MPLS
packets are distributed over a port-channel based on the MAC source and destination address. With
the lag-hash-mpls microcode, MPLS packets are distributed across the port-channel based on IP
source and destination address and IP protocol. This is applicable for MPLS packets with up to five
labels. When the IP header is not available after the 5th label, hashing for default load-balance is
based on MPLS labels. For packets with more than 5 labels, hashing is always based on the MAC
source and destination address.
ipv6-extacl Use this microcode when IPv6 is enabled.
acl-group For applications that need 16k egress IPv4 ACLs (for example, the VLAN ACL Group feature,
which permits group VLANs IP egress ACLs.
ipv4-vrf Apply to IPv4 VRF CAM profile.
ipv4-v6-vrf Enable IPv4 and IPv6 CAM profiles for VRF.