Arch Linux

big_gie

Member

Registered: 2005-01-19

Posts: 637

Server going crazy?

Hi all,

My i686 arch server is going crazy. This server host some subversion repositories (accessed via svn+ssh://) and a simple web page through apache.

Since this weekend, I have trouble connecting to it. Sometimes I'm able, sometimes not.

When I'm in, after around 2 minutes I get disconnected with:

> Read from remote host serverhost: Connection reset by peer
Connection to serverhost closed.

(who is peer anyway? and why is he disconnecting me? )

Then just after that I try to connect back and I get this:

ssh: connect to host serverhost port 22: Connection refused

Nothing in the logs shows something wrong. On the server, it seems sshd processes are still running, maybe they think I'm still connected?

After I get disconnected I tried accessing my web server and all I get is "403 Forbidden: You don't have permission to access / on this server."

Then maybe 5 minutes later I can connect back through SSH and the web page is back to!

I don't know where the problem could be. I though it could be the network but since I can access the web server and it is serving me a 403, the problem might reside somewhere else. Also, I cannot access the webserver localy, using "lynx 127.0.0.1", it timeout. I have "Listen 80" in /etc/httpd/conf/httpd.conf. I did not tried locally before that problem, so it might not be related...

The network card is:
02:08.0 Ethernet controller: Intel Corporation 82801BA/BAM/CA/CAM Ethernet Controller (rev 03)
using module "e100" and static IP.
eth0="eth0 192.168.0.10 netmask 255.255.255.0 broadcast 192.168.0.255"
INTERFACES=(lo eth0)
gateway="default gw 192.168.0.1"
ROUTES=(gateway)

Any ideas?

Thanx

Aaron

Member

From: PA, USA

Registered: 2007-12-19

Posts: 108

Website

Re: Server going crazy?

Did you recently upgrade any packages at all?

You're not running any sort of firewall-like solution are you?

It's almost like your computer is getting blacklisted for a specified amount of time.

big_gie

Member

Registered: 2005-01-19

Posts: 637

Re: Server going crazy?

Thanx Aaron,

I upgraded yesterday, after seeing that problem... There was only a couple of new packages, nothing related to network or kernel...

I'm pretty sure I don't have any firewall. Only /etc/hosts.{deny,allow} which allow sshd and httpd.

I rebooted, reseted iptables rules (http://www.faqs.org/docs/iptables/inclu … ables.html), same thing...

After being connected for 2~5 minutes, I get disconnected with connection reset by peer, than I'm kind of banned for 2 minutes, and I can get back...

I started a ping from the two computers. I get 10% packet loss (server to client ping) and 0% from client to server...

Both computers are pluged in a switch. I tried changing the server cable and the slot the server's cabel was pluged in...

Aaron

Member

From: PA, USA

Registered: 2007-12-19

Posts: 108

Website

Re: Server going crazy?

This is a shot in the dark, but I think you should try it.  Do you have any other ethernet cables lying around?  Try replacing the cables linking the devices in question, maybe it's as simple as a loose connection within the cable itself.

Have you tried connecting from another computer?  Possibly outside your LAN?  Try and connect with another computer to see if it will drop you, and also try connecting from another computer while your original machine is "blocked".

Also, there are configuration options that drop idle or inactive connections, are you actively using the connection when it goes down?

big_gie

Member

Registered: 2005-01-19

Posts: 637

Re: Server going crazy?

Thanx again aaron.

Try replacing the cables linking the devices in question, maybe it's as simple as a loose connection within the cable itself.

I though I already tried it, but I'll do it again just to be sure. Could a bad cable degrade communication only in one direction?

Have you tried connecting from another computer?  Possibly outside your LAN?  Try and connect with another computer to see if it will drop you, and also try connecting from another computer while your original machine is "blocked".

The LAN is behind a firewall, so the only option I have is to connect by ssh from the server to another server of mine and remote forward a port. Then I connect to that machine with ssh with local port forwarding and if the two ports matches on the remote machine, I can connect. This is what I am using since almost a year without problems and I'm forwarding ssh and http (for proxy). Now the server seems to disconnect itself from the remote machine and has problem connecting back...
I tried connecting to the web server from another computer from inside the lan and got the same 403 thing.

Also, there are configuration options that drop idle or inactive connections, are you actively using the connection when it goes down?

Normally I set up the options to keep alive, so the connection don't time out again and again. I did not touch any configuration since. But then, how could a sshd setting influence httpd? I was not actively typing something, but had 2 minutes before the connection reset. I often keep connected for hours without disconnection, so you can say I was "active" compared to normally.

Thanx again....