Some help on RX errors

[canpandave]

We are getting a lot of RX errors on 1 port of our 250DC switch, it is a P2P link using Nanobeams.

Anyone able to give us some guidance as to where to look to find the cause?

Receive Error Counters



Rx Drops
0


Rx CRC
9


Rx Undersize
0


Rx Oversize
0


Rx Fragments
48


Rx Jabber
0


Rx Filtered
39




Thanks

/d

[sirhc]

Hello canpandave,

It is best to post your entire ports detail drop down like this so it can be put into perspective.

CLICK IMAGE TO VIEW FULL SIZE

port.jpg (125.71 KiB) Viewed 9500 times

The number of errors in relationship to total number of packets is what you need to look at.

The Rx Filter I would ignore (discussed on other posts).

Do you have Flow control enabled on all ports and the devices connected to each port. Put up a screen grab of your Main Status Tab. You can see if Flow control is active on the Main Status Tab.

CLICK IMAGE TO VIEW FULL SIZE

Flow Control.jpg (201.18 KiB) Viewed 9500 times

I would also do a cable diagnostics on the interface and make sure all 4 pair report the same length. If the pairs do not show the same length then chances are your cable was damaged during install such as being stretched or kinked.

Also if you have an Ethernet surge Protector in line try removing the surge protector to see if the errors go away.

Lastly try moving the cable to another port and see if the errors stop, if the errors remain constant then you can assume there is nothing wrong with the port.

Lastly try replacing the radio to see if the errors stop.

Unless there is a bad port in your switch which you can test by changing the port and seeing if the errors follow chances are you have a bad cable, bad Ethernet surge protector, bad jumper, or bad radio.

Always break the problem down into simple steps.

[sirhc]

Also I have noticed at my WISP that when I had issues between the tower router and the WISP Switch I saw errors on the port connected to the radio.

The errors did not show on the port facing the router but did show on the port facing the radio. When I fixed the issue with the router which was a bad interface port on the router my errors on the port facing the radio went away.

[canpandave]

I was able to stop the errors by setting both the switch and radio ethernet port from auto to 100F, Will try a different port next time I have someone on site.

Thanks for the help !

/d

[sirhc]

I was able to stop the errors by setting both the switch and radio ethernet port from auto to 100F, Will try a different port next time I have someone on site.

Thanks for the help !

/d

Hard setting the Speed Duplex is generally NOT a good idea and often results in poor performance.

If you are going to hard code the speed duplex it is a good idea to test capacity in both configurations.

It is always BEST to figure out what is causing the errors but also you may find that your performance is better with the errors than with a hard coded port.