Arch Linux

flade55

Member

Registered: 2011-11-09

Posts: 1

Intel pro1000 speeds decreasing

Any help or ideas would be most welcome as this issue is really puzzling me.

I have an Intel Desktop Adapter PRO/1000 GT PCI NIC in my arch server and it is behaving very oddly.  When rebooting or re initializing the network with '/etc/rc.d/network restart' the card will perform at expected speeds of 100mbps for about 10 minutes.  After that it seems to drop down to 10mbps or slower and will never improve without the restarting network or rebooting.  Now my switch is merely 100T so I would not expect to get any speeds faster than that even though the card is gigabit capable.

Some info:

ifconfig :
        eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500  metric 1
        inet 192.168.1.111  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::21b:21ff:fec5:b10a  prefixlen 64  scopeid 0x20<link>
        ether 00:1b:21:c5:b1:0a  txqueuelen 1000  (Ethernet)
        RX packets 2329865  bytes 2419114860 (2.2 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1886981  bytes 2569841119 (2.3 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

dmesg | grep eth0:
[    5.742673] e1000 0000:05:01.0: eth0: (PCI:33MHz:32-bit) 00:1b:21:c5:b1:0a
[    5.742701] e1000 0000:05:01.0: eth0: Intel(R) PRO/1000 Network Connection
[   10.467148] e1000: eth0 NIC Link is Up 100 Mbps Full Duplex, Flow Control: RX/TX
[   26.896753] eth0: no IPv6 routers present

uname -a:
Linux frogger 2.6.39-ARCH #1 SMP PREEMPT Mon Jun 6 22:37:55 CEST 2011 x86_64 AMD E-350 Processor AuthenticAMD GNU/Linux

rc.conf network section (i've removed most of the comments in the file for this post):
# -----------------------------------------------------------------------
# NETWORKING
# -----------------------------------------------------------------------
HOSTNAME="frogger"
interface=eth0
address=
netmask=
gateway=
NETWORK_PERSIST="no"

What baffles me is how the card will start at a good speed and then after 5 or 10 minutes it goes to a comparative crawl.  I have tried setting the speed and duplex manually to 100/full by editing /etc/modprobe.d/modprobe.conf with no change in effect.  I have also tried disabling Flow Control but that seems to cripple the speed even further for whatever reason.  What is odd is dmesg reports the card operating at the correct speeds, but in practice it is not at all.

Again any ideas or suggestions would be hugely appreciated.  If i'm missing something obvious here or if there is a thread about this already that i missed I apologize.  I have limited experience with arch but am trying to learn.
Thanks in advance!

swanson

Member

From: Sweden

Registered: 2011-02-05

Posts: 759

Re: Intel pro1000 speeds decreasing

I have three of these nics and they work fine with arch. I would suspect your switch .

alphaniner

Member

From: Ancapistan

Registered: 2010-07-12

Posts: 2,810

Re: Intel pro1000 speeds decreasing

Maybe ethtool would be useful.  I only use it for getting connection speed, but it does a lot more than just that.

Last edited by alphaniner (2011-11-09 15:50:18)

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