Re: A question about ixg(4)

On Tue, 5 May 2026, Alexander Schreiber wrote:
> On Sat, May 02, 2026 at 02:20:04PM +0300, Staffan Thomen wrote:
>> Hello list,
>>
>> I have a pair of ixg(4) devices in one of my systems, 82599EB is the
>> model I think ("Intel(R) PRO/10GbE PCI-Express Network Driver, Version -
>> 4.0.1-k")
>>
>> Now I haven't used SFP+ before, but I have heard that there might be
>> vendor lock-in going on that some NICs only accept modules of their own
>> manufacture.
>
> Yes, Intel is particularly infamous for e.g. their 10G NICs typically only
> officially wanting to use Intel marked optics. So you can either buy the
> Intel optics or ... have optics marked as Intel. E.g. FS.com offers to
> mark transceivers/DACs as whatever vendor you need. Alternatively, one
> can use tools like the Flexoptix Flexbox to that that oneself.
>
> Similar revenue-enhancing games are also played by some switch vendors.
>
>> My question then is, will this be a problem for this intel one?
>
> Quite likely. Observed behaviour from Intel X553 on Linux with non-Intel
> DAC:
> - external "link detected" LED comes on and stays on
> - poking around with ethtool indicates that the "non-supported" DAC is
>   quite functional, but the NIC refuses to pass traffic because the DAC
>   doesn't say Intel
> Plug in a non-Intel DAC marked as Intel: all is fine.

I have found Intel NICs sometimes need a reboot to pick a new 
transceiver/DAC being connected (I've even seen similar with 10GBaseT), so 
do this first before blaming the signature on the transceiver.

Of course, as Alexander says, switch manufacturers (I'm looking at you 
HP/Aruba) do the same. This means that you want to use a DAC instead of 
transceivers and fibre, you don't really have an option EXCEPT to use 
third-party DACs as they can code each end differently.

I use gbics.com personally.

-- 
Stephen