I'm currently running a headless Ubuntu 10.04 server. Installed is the LAMP stack, Joomla, Virtualbox, phpvirtualbox, webmin and proFTP.. It resolves the IP address so I can access it remotely (either the apache2 webserver or the FTP) using DDClient. Any packages installed have been installed using apt-get. Webmin, although discouraged in Ubuntu Server, is used mostly to administer the webserver aspect. This issue also appeared when I was using Ubuntu Server 10.10.

After periods of heavy network traffic, whether local or remote, the connect drops. I'm talking specifically about the transfer of files via FTP, SCP or Samba (the latter of which I seldom use). There is no response to ping or ssh. I can't FTP to the server nor can I load the website. There are times when the server has been on for a few days and everything runs fine because I haven't accessed it much, if at all (thus not much network traffic).

I've gone through a few hardware changes although I don't believe this has cause the issue: this has been happening long before I made any changes. At first I thought it was my ISP-provided router blocking traffic because of some kind of misconfiguration (perhaps assuming it was some kind of DoS attack). I've changed routers and still found no success. I've checked syslog, dmesg and kern.log for warnings but have uncovered none. I've ran memtest via the GRUB2 menu at boot and once it turned up 4 errors. I ran again with individual sticks of RAM in various slots and everything turned up fine. I've looked through the BIOS settings and everything looks fine. I've tried unplugging unnecessary pieces of hardware (other internal hard drives, CD drives, floppy, PCI cards, etc).

Any help or tips on how I can even begin to troubleshoot this would be very much appreciated. Please note that i've only started playing with servers as a hobby so my knowledge wouldn't be the most refined. I'm comfortable with command line and have the initiative to know how to look up something I can't do. Unfortunately I can't seem to find any issues like this.

Additionally: If a solution can't be found some assistance to write a script that will cause the server to reboot automatically if, after x minutes, it gets no response to pinging somewhere like google. Admittedly that's not the cleanest solution should my internet end up going down but I can't think of what else to do.