Ubuntu freezes when downloading large files over ethernet

When you download the file, did you try downloading the file using wget or something similar? You can download a file via wget with:-
wget link-to-file
Also, what browser/download manager were you using to download the file?

I was trying firefox and perl www client. The system freezes at some point during the download, not right at the beginning. Sometimes in the middle of the download, sometimes almost when it starts. Another interesting thing is that when I was downloading the same file during rush hour, the speed was 3 times as low as in usual time and everything was fine.

I couldn't find a sutable link for wget (for firefox and www-perl I used rapidshare.com, but it's not OK for wget because I need to specify cookies...) But if you need wget, I can manage to do this with wget.

It freezes and during usual work, but it takes a lot more time. So, I'm confused. Maybe it is related to the size of packets. To large packets hang the system. Is it possible? What the tools to manipulate with it?

That is a very strange problem, did you try downloading the file using another PC to see if it is a problem with Ubuntu or if it's a problem with the file?

The problem is not with the file, because I download different files and the result is the same. I think the problem is in combination of my hardware and Ubuntu. But, since it works somehow, I hope that I can make it work stable.

Also, I would like to add that the problem is not in my network, because I had the same issue in hotels, my work, etc.

Hmm, that is very strange, can you just post the specifications of your PC? Could you also please post the output of:-
df

I have MS1034 laptop
the processor is Intel Mobile M T2500 Dual-Core, 2.0GHz, 2MB, 667FSB, 65nm
2GB of RAM
Here is lspci:
------------------------------------------------------------
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 2 (rev 02)
00:1c.2 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 3 (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #3 (rev 02)
00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #4 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e2)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus Controller (rev 02)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 01)
03:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 02)
04:04.0 CardBus bridge: O2 Micro, Inc. OZ711MP1/MS1 MemoryCardBus Controller (rev 21)
04:04.2 SD Host controller: O2 Micro, Inc. Integrated MMC/SD Controller (rev 01)
04:04.3 Bridge: O2 Micro, Inc. Integrated MS/xD Controller (rev 01)
04:04.4 FireWire (IEEE 1394): O2 Micro, Inc. Firewire (IEEE 1394) (rev 02)
------------------------------------------------------------

Could you please post the output of:-
df

Sorry, forgot about it :)
Here it is
------------------------------------------------------------
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda1 73963548 52227264 17979084 75% /
varrun 1033716 224 1033492 1% /var/run
varlock 1033716 0 1033716 0% /var/lock
udev 1033716 52 1033664 1% /dev
devshm 1033716 20 1033696 1% /dev/shm
lrm 1033716 38176 995540 4% /lib/modules/2.6.24-17-generic/volatile
------------------------------------------------------------

This is indeed a very strange problem...

How big is a "small" file? Please post the size of the biggest file you could download without problems.
Then please try to download that file multiple times to see if it still works.
After that please try to find a different file to download with a similar size and see if you can download that file without problems too.

And if you download a "large" file using your Wi-Fi connection your system does not freeze? Never or just not so often?

What type of file do you download when your system freezes? Compressed data like RAR ZIP DEB or the like?

Usually, I browse internet and view webpages without problems. So, typical size of "small" files is 50-200Kb. My "large" files are about 100Mb, those are archives, usually rar. I download different files every day of the approximately same size from www.rapidshare.com

Sometimes I can download a large file without a problem, but it happens very seldom. Usually the system freezes during this process. So, there is no maximum size that I can download. It is just the possibility that it will break the system. The larger the file - the greater the possibility.

I had absolutely no problems with Wi-Fi. My laptop worked for months without a reboot.

So my guess is that either your Ethernet hardware or driver is faulty, because you do not have any issues when using Wi-Fi.

I can think of two possible causes (which both should not happen, obviously):
 * Some "magic" data in a packet is the cause, which happens more often with compressed files, because they look like random data
 * To many packets send or received

To test for the latter can you connect your laptop to another computer via Ethernet and create many packets with this command:
$ sudo ping -f 192.ip.of.other.pc
Then you can watch the count of packets send and received using:
$ watch -n1 -d "ifconfig eth0|grep packets"
If your machine freezes doing this you have probably found the cause. Maybe the last packet count would be (near) some "special" number like 65536 (2**15) 32768 (2**15)

Have you tried another operating system?

I tried to count the packets. I ran watch twice. The first time I got the result
RX packets 6662, errors 0, dropped 0, frame 0
TX packets 5959, errors 0, dropped 0, frame 0

The second time it was
RX packets 18714, errors 0, dropped 0, frame 0
TX packets 14430, errors 0, dropped 0, frame 0

So, it does not look like the problem is in the number of packets.

I don't have any other OS on my laptop.

I have bought LAN2USB converter. Everything works perfectly now.

But thanks for your help, anyway.

I know this thread is old (like 5 years XD)
but I would just like to you let you know I have this exact problem now, on Ubuntu 12.10.

Perhaps I should invest in an ethernet -> usb adapter.