Ubuntu Networking Help needed!

[vdeane]

In one of my college clubs we have a server running Ubuntu 10.04 for our email lists and website, and formerly, everything else. Until three hours ago, it was set up to serve as our router, which had the unfortunate side effect of making everything slower than dial-up. Because of this, I reconfigured the network cables to use our wireless router as the router; most of the network is OK with this, but the server does not like it at all. It has no network access and even trying to ping the router by IP address gives the error "Destination Host Unreachable". I have no idea how anything with respect to the network was configured, and no idea what the problem is. Can anyone help? I've been pulling my hair out and am out of ideas; I think I might have to reformat the hard drive and start from scratch.

[vdeane]

Anyone? I'm absolutely desperate for help and am in way over my head. I have since attempted to remove the DHCP/DNS server and iptables (I thought there was a firewall rule causing problems and couldn't figure out how to disable it), and now it won't boot. I get to the point where I should have a login prompt but instead I have a non-responsive blank screen. Please help... I can't figure out how to fix this other than re-install, which would leave us with 100% data loss (I can't mount the drive with a live CD for some reason - caja just says "cannot mount drive", so there's no possibility of data recovery), and I don't know how to how to set up certain things (such as automatically mounting the storage on our automation system, or telling apache to forward all traffic to a certain directory to a different computer). I'm in over my head, the person who set this server up won't return my emails, and these issues need to be fixed yesterday. We have no way of contacting our members without our email lists, for example.

[catweazel]

Anyone? I'm absolutely desperate

Perhaps you should try the Ubuntu forums rather than Mint forums. There's nothing in either of your posts that would indicate your MATE desktop is the cause of the issues.

[vdeane]

It'll be a shame to have to make an account there just for this oee issue. Maybe I'll create a WCKN account for future use...

I managed to mount the drives (LVM/RAID) but I'm not sure where to put the data. Many files require root, which means I can't copy them to my server with caja... can't connect to it as root, can't copy the files as a normal user.

[kwisher]

Can you connect via SSH?

[DrHu]

http://martybugs.net/wireless/router.cgi

Based on host unreachable, your ifconfig status may show your IP address for that workstation is not on the same network as the server/router
--if you need to investigate/diagnose the problem and no network/sys admin is available to help ?, then you can check various network setups to find out some additional info for your network..
http://www.comptechdoc.org/os/linux/use ... icnet.html
http://www.ibm.com/developerworks/libra ... index.html

Basically you have to

• Check your routers web interlace and see the status of the network and devices (printers, client computers and any other resources (media streaming devices, email services etc..))
• Check that the client (the computer you connect from ) see the router's gateway as being UP and active..

http://www.computerhope.com/issues/ch001062.htm
--that's a windows example, however the Linux one would be similar, just like a windows, apple or Linux desktop services or look will be similar
[windows: ipconfig, ping, netstat]
[linux: ifconfig, ping, netstat (netbios status using names)]

Your own research will get you more detailed or more specifically useful to you guides/youtube examples or howtos: looking will find them
--and yes the desktop has nothing to do with the network interface failure (host unreachable)
--the network service: router and your client network device has to be ready and running..

[vdeane]

Re-installing ufw (if it got removed with iptables, I would have thought it would go back with iptables... guess not) got it to finish booting, and some work with /etc/hosts and /etc/network/interfaces got networking working. No ssh until I got networking up.

[kwisher]

Re-installing ufw (if it got removed with iptables, I would have thought it would go back with iptables... guess not) got it to finish booting, and some work with /etc/hosts and /etc/network/interfaces got networking working. No ssh until I got networking up.

Better make a backup while it's working!!

[vdeane]

I actually made a backup before I got everything back... it was when I was getting the MySQL databases that I remembered the /var/log directory and found the ufw problem.