Reference Guide
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
.
Troubleshoot CAM Profiling
The following section describes CAM profiling troubleshooting.
CAM Profile Mismatches
The CAM profile on all cards must match the system profile. In most cases, the system corrects mismatches by copying
the correct profile to the card, and rebooting the card. If three resets do not bring up the card, or if the system is running
an FTOS version prior to version 6.3.1.1, the system presents an error message. In this case, manually adjust the CAM
configuration on the card to match the system configuration.
Dell Networking recommends the following to prevent mismatches:
• Use the eg-default CAM profile in a chassis that has only EG Series line cards. If this profile is used in a chassis
with non-EG line cards, the non-EG line cards enter a problem state.
• Before moving a card to a new chassis, change the CAM profile on a card to match the new system profile.
• After installing a secondary RPM into a chassis, copy the running-configuration to the startup-configuration.
• Change to the default profile if downgrading to and FTOS version earlier than 6.3.1.1.
• Use the CONFIGURATION mode commands so that the profile is change throughout the system.
• Use the EXEC Privilege mode commands to match the profile of a component to the profile of the target system.
QoS CAM Region Limitation
To store QoS service policies, the default CAM profile allocates a partition within the IPv4Flow region.
If the QoS CAM space is exceeded, a message similar to the following displays.
%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3
Cam(PolicyQos) for class 2 (Gi 12/20) entries on portpipe 1 for linecard 12
%EX2YD:12 %DIFFSERV-2-
DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3 Cam(PolicyQos) for
class 5 (Gi 12/
22) entries on portpipe 1 for linecard 12
If you exceed the QoS CAM space, follow these steps.
1. Verify that you have configured a CAM profile that allocates 24 K entries to the IPv4 system flow region. Refer to
View CAM Profiles.
2. Allocate more entries in the IPv4Flow region to QoS. Refer to Configure IPv4Flow Sub-Partitions.
FTOS version 7.4.1 introduced the ability to view the actual CAM usage before applying a service-policy. The test
cam-usage service-policy command provides this test framework. For more information, refer to Pre-
Calculating Available QoS CAM Space.
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