Re: [E1000-devel] Strange packet dropping problem with PCI-Express built-in Intel NIC

[Auke K. <auk...@in...>]

Harry Edmon wrote:
> I have having a strange problem with built-in Intel gigabit NICs on new 
> motherboards with dual core processors.  I have had this problem both on 
> a SuperMicro X7DVL-E dual-core Xeon based server and an HP dc7700 Core2 
> Duo workstation.  The problem occurs in Debian etch distribution with 
> kernel versions 2.6.18, 2.6.18.1, and 2.6.19-rc1 with the included e1000 
> driver and the latest driver (version 7.2.9).  It also occurs with the 
> stock kernel on Centos 4.4.  It may occur with other kernels, but those 
> are the ones I have tried.
> 
> Here is where I see the problems.  I am running NIS (aka yellow pages).  
> The systems with the problems are NIS clients connected to a full-duplex 
> gigabit network.   The command that shows the problem is "id -G 
> <username>", where <username> is any of our users in the NIS database.   
> Sometimes when this command is executed it returns with no error 
> messages.  But sometimes it prints:
> 
> do_ypcall: clnt_call: RPC: Timed out
> 
> one or more times with a 5 second delay between the messages before the 
> command finally successfully returns.  In doing a tcpdump on the server 
> and the client, what you see when this occurs is the NIS server sends a  
> UDP packet that the  the client never sees.   After 5 seconds the client 
> times out, it prints out the error message, asks the server for the 
> information again and this time it sees the packet. I have tried many 
> different network switches and cables, none of the changes make any 
> difference.  I have tried it on the Supermicro Server with the ioatdma 
> driver in and out, no difference.  I have also tried several different 
> NIS servers (Sun Ultra 10, HP D310m), no difference.
> 
> Now, for some more interesting information:
> 
> 1. I tried putting a PCI Intel gigabit card into the SuperMicro server.  
> When I use that card to connect to the network the problem does not 
> occur.  Thus it is not a problem with all Intel NICS.
> 
> 2. I have a Dell Optiplex 745 with the Core2 Duo chips, but with a 
> Broadcom NIC.  The problem does not occur on this system.  Therefore it 
> is not seem to be a problem outside of the Intel NIC.
> 
> 3. "ifconfig -a" and "netstat -i" do not show any dropped packets.  
> There are no other error messages.
> 
> Although the "id" command eventually returns the information, we have 
> found cases where this delay in the NIS traffic causes our applications 
> to fail.  Our current operating hypothesis is that their is a problem 
> with the PCI-Express based Intel gigabit NICs.  Do you any reports of a 
> similar problem?

first things first:

which on-board NIC's are we talking about? can you include `lspci -vv` output, `dmesg`?

Feel free to raise a ticket in our tracker at e1000.sf.net.

I'm unsure whether a driver or NIC problem is at hand, it appears so but this is 
generally a very complex issue. Some distributions ship with default settings for e1000 
that we generally don't recommend at all. Check your /etc/modules.conf or modprobe.conf, 
but also `dmesg` will tell us.

This is the first report I've seen about this. It would be interesting to see the 
tcpdumps if possible.

Cheers,

Auke