topic RE: High "Rx Over" Error on a Port in ExtremeSwitching (EXOS/Switch Engine)

High "Rx Over" Error on a Port

Bnoba_CEO — Mon, 21 May 2018 16:51:00 GMT

Hi,

I have a port on a switch that is not congesting and the utilization is lower than 20 percent. Yet, Rx over error is so much - can run into millions in minutes:

Port Link Rx Rx Rx Rx Rx Rx Rx
State Crc Over Under Frag Jabber Align Lost
================================================================================
Port> A 0 9757092 0 0 0 0 0
================================================================================

Any advise please.

RE: High "Rx Over" Error on a Port

Ash_Curtis — Mon, 21 May 2018 16:58:00 GMT

Is the neighbouring device sending jumbo frames? If it is, and jumbo frames are not enabled on the receiving port, you will see Rx Over incrementing in this way.

This article from our KB explains how to enable jumbo frames and configure the MTU size in EXOS:

https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-enable-jumbo-frames

RE: High "Rx Over" Error on a Port

Naresh — Mon, 21 May 2018 16:58:00 GMT

Hi Bnoba,
Did you tired changing the cable and SFP if connected to the port?
If not, please swap the cable and the SFP if connected to the port and check if you area still seeing the RX CRC errors.

RE: High "Rx Over" Error on a Port

Bnoba_CEO — Mon, 21 May 2018 16:58:00 GMT

Hi Ash,

Thanks for your response. But jumbo frame is enabled on both devices.

RE: High "Rx Over" Error on a Port

Eric_Burke — Mon, 21 May 2018 16:58:00 GMT

Bnoba, I'd dig a bit deeper in the jumbo frame configs. The only way I'm aware of you getting this error is for a "receive overrun". Issue a "show port xx info detail" command on the ports in question and make sure they both enabled (you'll see "jumbo:" toward the middle of the list.

RE: High "Rx Over" Error on a Port

Bnoba_CEO — Mon, 21 May 2018 16:58:00 GMT

Jumbo: Enabled, MTU= 9000

Jumbo is enabled.

RE: High "Rx Over" Error on a Port

BradP — Mon, 21 May 2018 16:58:00 GMT

Might want to try configuring to 9216 instead of 9000.

RE: High "Rx Over" Error on a Port

Bnoba_CEO — Mon, 21 May 2018 16:58:00 GMT

Hi Naresh,

Thanks. I would explore this option.