Nexus 5548 - ERROR: no free statistics counter for a region

[th.oswald]

Hello,

I need a little help and I hope I find it here. In a little environment I have two nexus 5548 with L3-Daughter-Card. They do l2 and l3-switching, ACL-filtering and other things. For operating reasons I need statistic counters for all of my ACLs and I think everybody here can understand this. By now I configured 11 ACLs with over all 240 ACEs. That is really not much and as all I can see is that in the tcams are enough space for more. But now I want to configure a new ACL with just about 120 lines and the command "statistics per-entry" and when I try this the switches return the error-code "ERROR: no free statistics counter for a region". Is there a way to change the hardware resources to make it working? Or is there any other way to make it working? Any suggestions?

Regards

Thomas Oswald

[aaleston]

It seems it has reached the limit of Layer 4 operations (L4Ops). For typical configurations, the main hardware resources are the logical operation units (LOUs) that are combined on this platform between Layer 3 operations (L3Ops) and Layer 4 operations (L4Ops). The operator portion of an L4Op is one of the lt, gt, neq, and range operators. The operand is the source or destination TCP or UDP port number. Therefore, source or destination matched traffic uses a different operator. The eq operator does not consume an L4Op but Layer 3 operations (L3Ops).

* We have a limitation of 8 UDP and 8 TCP L4Ops per ASIC.

* When "statistics per-entry" is added to an ACL then it avoids rules from merging, which requires a bigger amount of TCAM memory, also temporary records with L4 operators may be created for optimization purposes - and if all L4 containers are used - an error will be shown.

We have seen the Nexus 5500 is capable of accommodating around 256 ACEs for which "statistics per-entry" is added.

However, you can expand/optimize hardware resources using: the "hardware access-list lou resource expansion" command. Then you need to save the configuration and a reload is required so that this command takes effect.