Ethernet only running half-duplex, 10M

[Musicalbudgie]

The ethernet on my rasp pi has been working great for the last week or so, set up with a static IP connected directly to my laptop. I went away for a couple of days and took the pi with me, even managed to watch an HD film on it over ethernet at someone's house.

Today I come back home, connect it up to my laptop using the same ethernet cable and I notice the network is running incredibly slow. If I look at the status lights, FDX and 10M are both off. cat /sys/class/net/eth0/speed reports "10". I don't think I've changed anything in the network configuration recently that might cause it. In /etc/rc.conf, I have

Code: Select all

interface=eth0
address=10.0.0.2
netmask=255.255.255.0
broadcast=10.0.0.255
gateway=10.0.0.1

The laptop static IP is set up using networkmanager. Both the pi and laptop are running Arch.

Is it possible something got damaged in transit? I kept it the anti-static bag it came in and wrapped that up in some clothes to keep it protected. I wonder now if despite it being in the bag, perhaps some static was generated by the clothes it was wrapped in..

Any other thoughts why it might not be working?

[mahjongg]

damaged in transit? No, then it would stop working altogether! The only reason the (any) Ethernet PHY would drop down to 10Mb is if the signal quality has degraded so much that 100mB operation won't be supportable.
I do see you are aware that the meaning of the LED is inverted from what is printed on the PCB, if the LED burns it means 100MB mode is used.

[johnbeetem]

Some suggestions:

When a 10/100 Ethernet over twisted pair first starts up, it tries to auto-negotiate the fastest possible setting. If auto-negotiation fails, both ends drop down to 10Mb/s half duplex as the default setting.

I would first try running "ping" for a while to see how well 10Mb/s HDX is working -- it may be that your poor networking performance is because of a large number of errors, which the higher communication layers deal with by retransmission. After all, 10 Mb/s is pretty fast by itself so if you're seeing poor network performance it's likely you're getting a lot less than 10 Mb/s. There may be a bad hardware connection somewhere. I have found that if one side of a differential pair fails you sometimes do get traffic, but it's unreliable. So first try different Ethernet cables in case yours has a broken wire.

It's unlikely that static would damage an Ethernet port from the outside, since the transformers provide a lot of electrical isolation. Do check the Ethernet jack carefully with a magnifier: there may be a bent contact. Also check that the Ethernet jack was soldered correctly, and double-check the resistors and capacitors between the Ethernet jack and the LAN9512 chip. Also check the contacts around the LAN9512 with a strong magnifier to see if a stray bit of solder is shorting out a pair of pins. Also check for missing components: one reader reported R41 was missing.

[Musicalbudgie]

Thanks very much for the detailed replies.

After a little more experimenting I've discovered that the problem lies with a configuration on my laptop and the pi is actually fine (it works connected to another computer).

I'll make another post on the Arch forums instead.

[nolex90]

Hi guys!
I noticed that my Pi runs on 10mbit ethernet speed.
I have checked all pins and soldering pads around the ethernet jack.
What should I do?

thank you

[ukscone]

are you sure it's running as 10M as i seem to recall Eben saying in a post somewhere that the 10M led is actually mislabeled.

[nolex90]

are you sure it's running as 10M as i seem to recall Eben saying in a post somewhere that the 10M led is actually mislabeled.

But, when i reach over sftp the file transfer is so slow, about 800-900KB/s.
Do you believe that there is something wrong in config file or the hardware?

[Lob0426]

Another culprit that appears to have been missed here is the Ethernet cable. I just had to replace one that allowed me to run at 100Mb but would not run at 1Gb. It used to work at 1Gb. If nothing else works try the cable.

[nolex90]

I have tried with two 1m cat5e cable and one 5m cable with two different routers.
The copy speed over winscp (sftp) is about 900 KB/S when i use vsftpd, it speeds up to 1400KB/s
So slow, but why? Can I do anything?

[nolex90]

So what should I do?
I need extra brandwith to store some unnecessary files on pi, or it can be used as a backup server.