hi there.. sorry to butt in but i have 'exactly' the same problem with ubuntu studio and the 'edimax .. works with everything..its included in the kernel'.. :-/ wireless card.. i managed to get it to work at one point by manually editing resolv.conf and adding a nameserver although this could be entirely coincidental.. the network manager is a complete POS.. it tells me i have no lan wlan0 when ifup wlan0 tells me otherwise.. i'd be interested to try wcid but i'll need to scavenge a 50 foot net cable first :-)
i'll follow this thread with interest

Hi everyone, Sorry I wasn't able to get back to the forums for a little bit, I was having a strange hard drive issue that was preventing me from even booting to Ubuntu in the first place (some file system error, dunno exactly what happened).

Anyway, I'm still using a static IP address to get online. Plus, I didn't know that Wireshark was cross-platform; I thought it was just a GTK frontend for tcpdump or something like that... I'll try it next time I have to reboot (In case I might not be able to get into Linux again...I'm still suspicious that fsck *might* not have done a truly appropriate job of "fixing" the file system. I've never used it before until now, so I don't know what to expect).

As far as the hard drive issue, I'll have one of us look at it in more detail to see if it's a hardware problem or not (it shouldn't be, I just got the drive brand new a few weeks ago). Now I know why I should back up; that was too close for comfort!

As you noted, the issue with the MAC address is probably not relevant since this seems to be an authentication issue, but I thought maybe I should try to clarify this. It is quite common on an ethernet connection (and I assume, wireless) for a machine to use ARP to find out the MAC address that corresponds to an IP address. If you run a packet sniffer on a normal connection, you will see this happen fairly frequently. While apparently the ARP cache can be manually manipulated with, for example, the arp command, I doubt that is what the entry in the "Edit Connections" dialog is for. (My most recent Ubuntu is 8.04, which I don't think has that dialog.) My *guess* is that is for changing the MAC address of your interface. If so, you certainly would not want to set it to the address of the router (or antyhing else on the LAN).

I doubt that you want to go playing around with the ARP cache unless you really know what you are doing. But I am willing to accept the instruction of others on that point.

So it sounds like an authentication issue. If you can do so w/o disturbing others in the household too much, you might want to temporarily turn off authentication/encryption on your router and see if you can connect w/o problems. If so, that would definitely demonstrate the problem is authentication. While you are looking at the router settings, double check what types of encryption (wpa, wpa2, etc) it is setup to accept and make sure that matches the configuration on your computer.

If you want to get into the real nitty-gritty of authentication, you can tell [b]tcpdump[/u] and Wireshark to capture the entire packet so you can look at content. (That's way beyond anything I've done.)

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I keep wondering if maybe the communication with the wireless adapter isn't quite right. But I don't have any idea why power cycling the router would straighten things out. Just random thoughts while we are groping for a solution.

EDIT: I just realize that my suggestion to try temporarily turning off authentication has is complicated by the fact that simply power cycling your router seems to fix the problem. So I don't know of an *easy* test.

Thanks for the detailed reply. I will say that I have tried other types of encryption before, most notably WEP, and that seems to allow me to connect, but then the other computer that needs to connect wirelessly (a Windows laptop) can't seem to manage a stable connection. I don't think disabling encryption is an option either, simply because we'd like to keep the router secure (not my decision).

In the meantime I guess I'll just have to deal with resetting the router to get a net connection...for now it's easier than booting to Windows just to use the internet (going back and forth between OSes that frequently? Ack!).


..Just as a short note, does anyone have any good suggestions for Linux-based disk image backup software? Preferrably freeware, if possible. Doesn't necessarily have to be FLOSS. I've determined that my WD hard disk (the one with Ubuntu on it) is failing, and I can't seem to get rsync to work on /. I'll open a separate thread on this issue if need be.

Understood. I was suggesting it simply as a diagnostic tool to make sure everything other than encryption was working. Then I realized that changing that setting would likely involve a reboot of the router. Given that a reboot seems to solve your problems anyway, it would not be much use as a diagnostic. :-/

BTW, I don't know if you are already aware of this, but WEP has been known to be broken for a long time. Just recently somebody announced they can crack WPA in under a minute. (I don't know if the talk where this was to be demonstrated has happened yet or not.) So for "consumer grade" solutions, if you want your wireless to be secure, you need to use WPA2.

I've used partimage. A number of different live CDs contain it, including SystemRescueCd. It's main drawback is that if you want to send the data over a network, you must run partimaged on the remote computer. That too can be found on live CDs. (Knoppix used t o have both -- probably still does.) Unless you really need it, I would suggest you not use the compression since that is likely to slow things down. Something you dont need if the disk is failing.

If you just want to make a bit-for-bit copy of the disk (or a partition) and don't want to do anything fancy, dd will do the job. Since you are likely to be hitting bad blocks, dd_rescue might be more appropriate. It has a front end called dd_rhelp which is supposed to help more. (Disclaimer: I have not used dd_rhelp and have minimal experience with dd_rescue.) The output of dd (and I would guess the others) can be piped into ssh for easy transportation across a network. With a little more work but less overhead you can also do it with netcat running on each end.

Make sure you have everything lined up before you start so you don't excercise the disk unnecessarily. And definitely make sure you do any prior downloading and research from another machine!

BTW, just see what happened, I started up rsync to copy from / with the -a option. . As soon as I saw it was copying (verified on the other end) I stopped it. You probably want to exclude /proc and /sys. But you also don't want to waste time with a failing disk trying to get something to work. It is also possible it was having trouble due to bad sectors.

Good luck.

(If you need more info, you probably should start a new thread.)