Core issue
The %QATM-4-TCAM_LOW: TCAM resource running low for table [chars], resource type [chars], on TCAM number [dec] error message indicates that the hardware ternary content addressable memory (TCAM) resource is running low and could cause system instability. The first [chars] is the TCAM table, the second [chars] is the resource type, and [dec] refers to the TCAM number.
The error message means that the TCAM table is reaching its maximum capacity to store information. It is an informational message not an error.
Resolution
If this error message is received, avoid further configurations that could deplete the indicated TCAM resource type running low. Issue the show tcam user EXEC command to display information about the input security Access Control List (ACL), the output security ACL, the Quality of Service (QoS), or other regions of the TCAM as shown in the message TCAM table.
Issue the sdm prefer global configuration command to configure the template used in the Switch Database Management (SDM) resource allocation. If possible, change to a different TCAM allocation.
Also, try these workarounds:
- Summarize to make the ACLs smaller.
For more information on this, refer to Configuring IP Access Lists.
- Issue the sdm prefer access command in global configuration mode to maximize the security ACL TCAM size.
Note: The switch needs to be reloaded for the configuration to take effect.
For more information on how to increase the TCAM, refer to Understand and Configure the Switching Database Manager on Catalyst 3550 Series Switches
