[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Intel X540-AT2 and Debian: intermittent connection



On Fri, 2022-11-18 at 17:02 -0800, David Christensen wrote:
> On 11/18/22 05:23, hw wrote:
> > On Tue, 2022-11-15 at 16:42 -0800, David Christensen wrote:
> > > On 11/15/22 07:15, hw wrote:
> > > > On Tue, 2022-11-15 at 12:38 +0100, hw wrote:
> > > > > On Mon, 2022-11-14 at 13:21 +0100, hw wrote:
> [...]
> > > What is the cable type?  Length?  Factory or home made?
> > 
> > I got a new cable today which is rated as cat 8.1.  It's only 1.5 meters
> > long.
> > I have tried 3 different cables now, two of them about 1.5 and another 10
> > meters
> > long.  Before I got the new cable, I tried the other port on the nic, and it
> > made no difference.
> > 
> > Even with the new cable, the connection is intermittent :(
> 
> 
> Different category cables have different characteristic impedance, and 
> the NIC's are designed for specific cables.
> [...]
> So, I suggest trying a Category 6A factory patch cable at least 2 meters 
> long.

I tried it with a 10m cat6 cable and the connection was intermittent.  It's the
same (as in "identical to") cable that works between the other server and a
client.

> > > What is connected to the other end of the cable?  If it is a NIC in
> > > another server, what happens if you swap the two NIC's?
> > 
> > It's connected to a Broadcom NetXtreme II BCM57810 in another server.  The
> > other
> > server has an identical mainboard and CPU in it, and the other port on the
> > Broadcom is connected to a client with the same card, and that connection
> > works
> > fine.  So I'm assuming that the Broadcom card is ok.
> 
> 
> What OS's for the various machines?

Fedora on the server and Debian on the backup server, Fedora on the client.

> Do you compile your own kernels and/or NIC drivers?

No, I'm using the kernels that come with the distributions.  I did compile the
driver (i. e. module) from the source on Intels web site to see if a different
driver would make a difference, and it didn't, so I restored the "original"
module.

> > I'm about to move the client into a new case in a couple days and then I
> > might
> > swap the Broadcom from the client into the backup server.
> 
> 
> If you have another Broadcom NIC, what happens if you swap it with the 
> Intel NIC in the backup server?

I haven't tried yet because when I swap cards around, I'll have to redo the
configuration and the server has some network cards passed through to a VM
running OPNsense.  I don't want to mess with that.

I suspect it's a mainboard issue.  I pulled the Intel card and then the on-board
network card quit working.  I plugged the Intel card back in and the on-card
worked again.  I'd try disabling the on-board card but there is no option to do
that in the BIOS.

> > Maybe I can reseat the heat sink on the card with new thermal paste.
> > Overheating might explain why the connection is intermittent.
> 
> 
> Do you have any diagnostic information that indicates the Intel NIC is 
> overheating?

No, the idea that it might overheat is from internet searches revealing that
some people had issues with the card overheating and adding a fan blowing on the
heatsink fixed the problem.  I always had a fan blowing over it from the top of
the card, so that should be fine, and placing another fan directly on the
heatsink didn't make a difference.  I took the extra fan out today when I was at
it because it's awfully loud --- it's an old Delta fan from 2003 that comes from
an old IBM server and it makes a good airstream :)

The heat sink looks fine and unfortunately, it's designed in such a way that I
can't remove it without breaking the pins holding the heatsink to the card, so I
decided not to touch it.  That's how I discovered that the on-board network card
quit working when the Intel card wasn't plugged in ...

Perhaps it's some kind of resource conflict or incompatibility, or the board is
broken.


Reply to: