# What could cause sudden massive increase in packet loss on home Ubuntu 8.04 server?

This server has been running like a dream since I got it about a year ago. Torrent slave, NGINX webserver, CUPS print server, game server, and it got great uptime.

This past month or so, I have started to get huge packet loss in my connections to the server. I was editing something on it with Gedit (forwarding X over SSH,) and all the sudden it locked up and started getting very unresponsive. It has basically never gotten better since then. This has gotten so bad that even text-only SSH sessions are frequently unusable. Other people joining the game server have confirmed that it is basically unplayable (one guy called it a "flashback to the 70s.") I got a new router, that didn't solve the problem. (Don't regret buying it though, it's a big improvement in other ways.) I know it's not my modem because it happens via my LAN as well.

OS is Ubuntu 8.04, which is up-to-date.

Load on the server seems fine, CPU usage is almost never over 25%, everything is normal.

My Internet connection as a whole is also fine.

CPU: Pentium II (Deschutes core) @ 400 Mhz
80 Gb HDD (new)
192 Mb RAM
360 Mb Swap

max@server:~$lspci 00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 03) 00:01.0 PCI bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 03) 00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 02) 00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01) 00:07.2 USB Controller: Intel Corporation 82371AB/EB/MB PIIX4 USB (rev 01) 00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02) 00:0e.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10) 00:14.0 Multimedia audio controller: Ensoniq ES1371 [AudioPCI-97] (rev 06) 01:00.0 VGA compatible controller: 3Dfx Interactive, Inc. Voodoo 3 (rev 01) max@server:~$


There's a lot of different attributes of any system of course, and I'm not sure which ones are relevant-- if you need anymore information don't hesitate to ask.

Have any "old hand" Linux server admins ever seen anything like this before, and if so what caused it?

Thanks, -Max

EDIT: Error counter is pretty high:

max@server:~$ifconfig eth0 Link encap:Ethernet HWaddr 00:0e:2e:45:0c:a1 inet addr:192.168.1.103 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::20e:2eff:fe45:ca1/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:9519234 errors:49527 dropped:0 overruns:1 frame:0 TX packets:13950328 errors:0 dropped:0 overruns:6 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2429542473 (2.2 GB) TX bytes:3878514896 (3.6 GB) Interrupt:9 Base address:0xd800 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:463089 errors:0 dropped:0 overruns:0 frame:0 TX packets:463089 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:82642330 (78.8 MB) TX bytes:82642330 (78.8 MB) max@server:~$


EDIT2: Maybe this could be helpful (it is the output of netstat -ees, and it is big enough that I put it on pastebin.) http://pastebin.com/AWfkF8Vh

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"I was editing something on it with Gedit (forwarding X over SSH,) and all the sudden it locked up and started getting very unresponsive" ... what exactly where you editing, and what changes did you make? –  Zypher Feb 25 '10 at 2:14
Doubt that matters, but this was about a month ago so I don't remember. It wasn't any config file or anything, I remember that. (If it was, it would have been running with elevated permissions and the dark theme wouldn't have been in effect.) –  Max E. Feb 25 '10 at 2:17

Well, you don't give a whole lot of info, so all I can do is offer a suggestion. Have you tried connecting directly to the server w/ a crossover cable to see if packet loss persists? Perhaps you have a bad switch port.

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I did get a new router, and yes I have tried this as well. Is there any info I could edit into my question which would help? Thanks for the answer. –  Max E. Feb 25 '10 at 2:41
Packet captures, network interface error counters to start. It could be a bad network card - you could try throwing a cheap \$15 NIC into the server and switching over to that instead of the Realtec card. –  EEAA Feb 25 '10 at 3:16
Cool, I'll look into that. I'm also going to get some new cable, will post if that fixed it. –  Max E. Feb 25 '10 at 3:18