[RndTbl] sshd: Corrupted MAC on input.

Gilbert E. Detillieux gedetil at cs.umanitoba.ca
Mon Aug 10 11:28:46 CDT 2020


I have one system where that was an issue.  It resulted in a more 
distinct error message, which I was able to search for, and find the 
solution you mention.

This one is a different Intel chipset, and a different error.  (I don't 
think this NIC even supports TSO; and the GSO/GRO options don't seem to 
be the problem.)

Thanks,
Gilbert

On 2020-08-10 11:19 a.m., Alberto Abrao wrote:
> I don't run any heavy workload such as this one, but I would not be 
> surprised if that fixes your problem for good. I had quite a few issues 
> with Intel NICs on Linux - especially with the 3.x kernel - that were 
> solved by disabling GSO/RSO/TSO.
> 
> Kind regards,
> 
> Alberto Abrao
> 204-202-1778
> 204-558-6886
> www.abrao.net
> 
> On 2020-08-10 10:57 a.m., Gilbert E. Detillieux wrote:
>> On 2020-08-04 1:28 p.m., Gilbert E. Detillieux wrote:
>>> On 2020-08-04 12:55 p.m., Adam Thompson wrote:
>>>> I can't remember, did you try disabling HW offload on both sending 
>>>> and receiving ends already? (Either end could trigger the SSH abort.)
>>>
>>> I hadn't yet.  (I was trying a few other things first, such as 
>>> changing MAC algorithms, and rebooting with the older kernel, neither 
>>> of which seemed to affect things.)
>>>
>>> I've now disabled both rx and tx checksum offloading.  We'll see if 
>>> that makes a difference.
>> So, after almost 6 days running with rx and tx checksum offloading 
>> disabled, not a single "Corrupted MAC on input" error!  My overnight 
>> rsync now runs to completion.
>>
>> I hope this isn't premature, but I think we found the problem! (Who 
>> would have thought it could make such a difference?!)
>>
>> It also doesn't seem to have caused a noticeable performance hit. I'm 
>> thinking we were disk I/O bound on the remote (receiving) end, anyway, 
>> so if the network I/O is a bit slower, we wouldn't see it.
>>
>> Thanks, everyone, for your suggestions!
>>
>> Gilbert

-- 
Gilbert E. Detillieux        E-mail:  <gedetil at cs.umanitoba.ca>
Dept. of Computer Science    Web:     http://www.cs.umanitoba.ca/~gedetil/
University of Manitoba       Phone:   (204)474-8161
Winnipeg MB CANADA  R3T 2N2  Fax:     (204)474-7609


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