No link with Supermicro A2SDI-TP8F

RTM

Active Member
Jan 26, 2014
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I have been trying to troubleshoot an issue I have with getting a link on the SFP+ ports of my Supermicro A2SDI-TP8F motherboard and my CRS326 switch (the cheap version with 2x sfp+ and 24x 1g) with a Mikrotik DAC cable.

As I am at my wits end, I am posting this here in the hope that someone here knows what to do?

Here are some of my observations:
  1. No link between switch and either of SFP+ ports on motherboard
  2. Link between port 1 and 2 on switch
  3. Link between port 1 and 2 on motherboard
  4. Using a different DAC cable made no difference (Brocade, probably active DAC whatever that means)
  5. Disabled autonegotiation on switch made no difference
  6. Unable to change autonegotiation, link or duplex with ethtool in Linux
  7. A different linux distro made no difference, nor did a newer kernel
  8. Link between switch and a different machine with a X520-DA1 NIC
  9. No link between motherboard and different machine with a X520-DA1 NIC
All of this leads me to think that the issue is not with the switch, but with the SFP+ ports on the motherboard.

I am thinking I need to try with a pair of transceivers, but as I do not have any, I would like to wait a little while, at least in the hope that someone here has some good ideas.
 

j_h_o

Active Member
Apr 21, 2015
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California, US
I'm using an FS.com SFP+ DAC that I got coded for Intel NICs, but with my X10SDV boards, which have a different SOC.

How far is your board from your switch?
 

RTM

Active Member
Jan 26, 2014
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I'm using an FS.com SFP+ DAC that I got coded for Intel NICs, but with my X10SDV boards, which have a different SOC.

How far is your board from your switch?
At the moment the switch itself is on top of the machine with the A2SDI board (both of the DACs I have tried were 1m).
It is not a permanent location, but the permanent one is no different.
 

Andres Giraldo

New Member
Jan 19, 2020
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I recently had a similar issue with A2SDi-H-TP4F, couldn't get it to work with a home switch SFP+ port over DAC. However in the office it would work fine when connected to a 10Gbps SFP+ port. Did an ethool on the port and it shows that the only support link mode is 10000, whereas normally I see 1000 , 10000, etc.. Came to the conlusion that it only works at 10Gbps. If run ethool -i XnicX what link speeds does it show it supports?
 

RTM

Active Member
Jan 26, 2014
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I recently had a similar issue with A2SDi-H-TP4F, couldn't get it to work with a home switch SFP+ port over DAC. However in the office it would work fine when connected to a 10Gbps SFP+ port. Did an ethool on the port and it shows that the only support link mode is 10000, whereas normally I see 1000 , 10000, etc.. Came to the conlusion that it only works at 10Gbps. If run ethool -i XnicX what link speeds does it show it supports?
Interesting, I can't find the specs of the Brocade DAC cable (58-1000026-01) but the Mikrotik one claims to support both 1 and 10g and both are reported by the switch to be of the type "SFP-or-SFP+". Using that logic I may need to get DAC cables/transceivers that only claim to support 10g.

Regarding the ethtool command it did not return anything about supported link modes, however without the "-i" (not trying to be rude here, just stating fact) it states that it only support "10000baseT/Full".
 

RTM

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Jan 26, 2014
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Posting this for the people who may find the thread via Google:

A different DAC and transceivers did not help.

After having moved the motherboard into a new case, the problem appears to have been resolved.
I am not sure whether the problem was a result of something shorting out somewhere in the old case, the old PSU being bad or the old case having poor airflow (U-NAS NSC-800).