Excessive CRC/Alignment Errors on port 19

[Alberto Frosi]

Hi all
Last night a hp switch 4108 for more port report
this error: Excessive CRC/Alignment Errors on port XX.In the same switch are connected more instrument HPLC and 1 server.
The server at 2.11AM has last the connection with all instruments and with another server connected in another switch.This error are appeared for any port too in the same switch.
What can i check for resolve the problem?
Till 15 January what this problem on the switch apperead!
Thanks a lot in advance.
Regards...
Alberto Frosi

[Ladrouz]

Hi,
Excessive CRC... means a bad negotiation.
Is port speed/duplex correct ?
Disable lacp on port that do not need i.
bye

[Alberto Frosi]

Hi,
There's this error too in the same swicth!My question is, what can i do for reduce the broadcast on this switch?
Where can i operate for solving this problem? In the switch or in the instruments (PC, client or anything else)?
Thanks a lot.
Best regards
Alberto

[Vasilij K. Savin]

First of all you should to check the cable connected to the port. Do not trust multimeters - use normal network analizer to measure NEXT, attenuations, wrong pairing etc.
Next, check the speed/duplex settings on both sides.
Next, monitor network traffic of your host, connected to the port. You can use WireShark (freeware tools, Google for it) for this purpose (it is available for *NIX and Windows as well).
Next localize the application generated this traffic. Tools will depend on OS you are using.

P.S. Of course, not all steps will be mandatory ;)).

Good luck!

[Joel Belizario]

You've been given some good advice, just a little more info in case you need it, this is an excerpt from the ProCurve website:

https://www.hpe.com/in/en/networking/switches.html

How many errors are too many?

Data link errors such as CRC errors, alignment errors, and runts will occur on healthy networks. How do you distinguish between a reasonable number of these errors and too many? A rule of thumb is one error in 5,000. For example, on average, for every 5,000 packets received you should have no more than one receive error (CRC, alignment, runt, short, giant, or too long). And on average, for every 5,000 packets transmitted, you should have no more than one transmit error (late collision, excessive collision, late event, excessive deferral, or loss of carrier). At higher rates of errors, users will probably perceive the network's performance as being poor.

One data link error in 5,000 does not necessarily indicate a perfectly-performing network. Rather, it indicates a network where the errors are probably not causing serious performance problems that are apparent to the users.