MS425-16 - Network port disconnected

[Kydu250]

Good morning,

we have installed two new MS425-16 switches with original CISCO cables and on some servers we have noticed an abnormal behavior.

When connecting the cable on one of the ports does not link, we change the port with the same cable and sometimes it works. We tried to change the cable to an HP one and the same thing happens.

These trouble we have since we installed the new switches.

We recently bought a new server and left it installed for testing and the same happens.

With the same cable on another port works.

The NIC model is AOC-MTG-i4S (https://www.supermicro.com/manuals/other/AOC-MTG-i4S.pdf). Could it be some PoE or BPUs?

Thank you in advance

[PhilipDAth]

What kind of cable are you using?  What is its part number?

[Kydu250]

Hi Philip, 

Thank you for your message. 

The cable is Original Cisco Meraki  MA-CBL-TA-3M.

Regards

[cmr · Accepted solution]

@Kydu250 we have used quite a few twinax DAC cables and they are VERY fussy.  We have found that Dell cables with Dell switches tend to work quite well when connected to Pure arrays, Dell cables connected between Dell servers unsurprisingly work well, but Dell cables into HP switches don't work.  Between manufacturers you are much better using fibres and the manufacturer supported SFP+ modules.

The issue is that with a DAC the devices at both ends have to be electrically compatible and this doesn't always seem to be the case.

[PhilipDAth]

I've never had an issue with twinax cables, ever.

I've only ever used the Meraki or Cisco Enterpeprise ones.  Mostly into HP and Cisco servers, and whatever storage system is flavour of the month.

[Kydu250]

@cmr Thank you for you menssage.

I'll check about electrical compatibility.