NX is a pain to set up. Maybe it’s just my bad luck that something goes wrong every time I try to set it up, or perhaps I’m just plain stupid but I find it a pain and it normally makes me feel like chewing my ethernet cable after a while. A long while back I managed to get nxserver-freeedition working fine, but recently it stopped and in the process I decided to switch over to using FreeNX – an open-source implementation of NX. Here is how I got it up finally, mainly for archival purposes.

Before starting, you may want to clean your system. unmerge nxclient nxnode nxserver-freeedition nxserver-freenx, etc, rm -r /usr/NX (if freeedition), rm -r /etc/nxserver (if FreeNX), remove the nx user and the nx group, rm -r ~/.nx/ for all users.

1. emerge nxclient
2. emerge nxserver-freenx
3. nxsetup --install --setup-nomachine-key --clean --purge (the –setup-no-machine key option means that you just need to use the default key that the nxclient comes with)
4. Try to connect via nxclient, tail -f /var/log/messages, if it complains about the user being locked, do usermod -p foo nx, where foo is a password you’ll use.
5. Start debugging why it doesn’t work.

When debugging I normally:

• Make sure SSH works first. Refer to my sshd_config (obviously this is specific to my setup, but notice that PasswordAuthentication is set to yes, as that’s how you’ll authenticate with NX with nxclient)
• Make sure you own your own authorized_keys(2) file, after a while of mucking about you might’ve screwed the permissions (600).
• Check that you’re pointing at the right authorized_keys(2) file, though I didn’t need to bother about this with FreeNX, I know that this is a common mistake with nxserver-freeedition
• I like to run SSH on port 443, so change to port 443 in /etc/nxserver/node.conf for FreeNX, and if using freeedition in /usr/NX/etc/server.cfg, node.cfg, whatever is specific to your setup.

As for my experience switching over to FreeNX from freeedition, honestly in terms of usability it’s no different at all, but personally in terms of installation procedure FreeNX wins by a mile. But for the moment I’m just happy I won’t be restricted by my school’s web filtering system and glitchy, laggy, virus-filled OS. Perhaps when NeatX stabilises a little I might check it out.

No related posts.

For those that don’t know what SSH is, it is basically a network protocol (for example like FTP, SMTP, etc) that allows you to securely connect to another computer. For those that don’t speak jargon, it is some cool thing that allows me to use my computer remotely.

One of my well-visited locations is my college. I wonder why :P … and like most places, it runs Windows. Using a Windows computer leaves me feeling crippled and with a sense of repulsion at the most innocent of small creatures. Combined with my college’s restrictions, there is a lot of stuff I can’t do. For example, I can’t download a .doc file. Also, it is quite troublesome to constantly transfer files over with a memory stick, so I decided to set up SSH.

Little did I know how pathetically paranoid the IT technicians were.

Problem 1: setting up SSH and connecting to my dynamic IP.

The first step was to install (emerge openssh) and set up SSH. (I run Gentoo- the steps will be different for your distribution or if you are running Windows – say, you can set up SSH on Windows, can’t you?) This was simple. Now the problem here is that my IP keeps on changing. Especially because my ISP’s connection is quite volatile, my IP is dynamic and resets several times a day. The method to solve this was to set up a dynamic dns, available from dyndns.org. This is a free service, and allows me to connect to a sane domain name whilst a client running on my machine updates it regularly on the latest IP.

Problem 2: port 22 is blocked.

The next day I popped PuTTY on a thumb drive and tested it out – or at least tried to. I had a network connection refused error. Later that night I learned that most public networks blocked certain ports, for example port 22 which SSH normally uses.

The fix around this was to change the config in /etc/ssh/sshd_config to use Port 443. You see, whilst http:// defaults to port 80, https:// URLs default to port 443 – and are hence rarely blocked. Et Voila – you can now connect! However, I also run an Apache webserver. This clashes as it also tries to use port 443. As I don’t care to serve SSL webpages on my localhost, I decided it was a decent sacrifice, and I removed Apache’s HTTPS support by removing `-D SSL -D SSL_DEFAULT_VHOST` from /etc/conf.d/apache2. Tada. I can now access SSH at my college.

Problem 3: What about SCP? Surely you’d want to copy files over.

Well, transferring files over is another issue. It’s all good with your vast array of Command-Line-Interface applications for IRC, Vim text editing, file browsing, MSN, email, calendar and PIM, etc – but every so often you will have the need to transfer a file over. Sending yourself an email with a file doesn’t help, as my college blocks almost every single website out there aside from Google.com (note: Gmail is not Google.com – so it is blocked too). At the same time, it also blocks downloading every single file type aside from image files. The quick fix for this was to put the file on my Apache localhost, change the file extension to a .jpg or something then download it from there.

But no. Two problems occured. 1) My website was blocked – haha, and 2) the IT technicians filter it not by extension, but by actual file contents. To get past the website block, I run a proxy script on my webserver (there are plenty of free proxies out there too) to access my webserver. But then of course I’m stuck with the file filter. So looks as though it’s game over.

Not really, there’s always SCP. I couldn’t send files using my computer as I didn’t know the network information of my college network. So I decided to SCP using the college’s Windows computer. I hear there’s a program known as WinSCP which is pretty nifty, but at the time I only had PuTTY’s collection of tools and thus PSCP.EXE – which pretty much did the same thing – with one catch: it’s a CLI application. You see, they’ve also blocked the command prompt. OK – for understandable reasons.

To get myself a command prompt, I did the age old innocent command.com trick. This involves creating a plain text file (eg: .txt), putting the words `command.com` in it, and then saving it as cmd.bat. (Notice the changed file extension). This will give you a prompt to work with. Now – using that to run PSCP.EXE, I succesfully transferred my target file over – which was in this case a .doc file, which contained some homework.

What about the ethics of this?

Well. I personally feel as though these workarounds are anything but a way for me to do my work conveniently. The computer system is riddled enough with viruses as it is without my doing, and I doubt anybody will be motivated enough to have such a complicated setup unless they were either particularly vicious or needed a file really urgently (such as me at the time). But seriously – a learning centre blocking .doc files?

If you have more experience in networks than me and feel as though this article is innappropriate, feel free to contact me and I’ll willingly take it down.

No related posts.

Right now, being 00:18AM (and counting!) I’m going to continue this series to talk about a few hidden tricks and activities you could use your computer for that you might not be accustomed to normally.

RSS Feeds

It’s amazing how many people who don’t know what an RSS feed is. RSS stands for Really Simple Syndication (yeah, really) and is basically a format of a web feed. In technophobe terms, this means it’s a fancy new way you can access information. For example, you can access your emails through your email client, you can view web pages with your web browser, and now you can view RSS feeds with, well, an RSS aggregator (or reader). Ok, it’s more complex than that, but that’s all you really need to know.

Let’s use a practical example to explain the usefulness of an RSS feed. Let’s say you absolutely love the thinkMoult blog, and you want to keep up to date on it all the time without getting extra spam in your inbox notifying you of updates. Well, like most blogs, we offer an RSS feed (hint: that was a link to our feed URL) You can input that URL into your RSS aggregator (which is a program you can download), and you can now easily view each post just as it is: a snippet of information, instead of laid out in this bulky (though beautiful) webdesign. It allows you to quickly parse information from all around the web in bitesize pieces. Don’t read too many blogs? You can also use it perhaps for comics, such as Dilbert or XKCD. Now you don’t need to remind yourself to check those pages for updates every time you’re online.

Multiple IM Protocols

Now, that’s just a fancy and technical way of saying MSN Messenger isn’t the only thing that exists. You can use Skype! You can use Jabber (such as GTalk), Yahoo chat, and there are so many other popular IM services that people use, you might just need to sign in to those accounts to make sure you can contact all your clients or important whomevers you meet online. I personally use Skype, MSN, and GTalk all the time.

You might find it’s a hassle to manage the multiple accounts, but fear not! There are less handicapped programs than your Windows MSN Messenger that actually support multiple protocols! For example, I use Kopete on KDE, and I can sign into all my accounts (save for Skype) with just one client. It really makes life easier.

Also, I know it isn’t exactly IM, but you should also familiarise yourself with IRC. IRC stands for Internet Relay Chat, and it’s what the whole online community used before other things got invented. Right now it’s still a massively popular form of communication, though mostly populated by people of the more intelligent and technical sort. It’s basically a huge chatroom (think 800 people per channel) categorised by topic. There are many IRC servers, though the most common is arguably irc.freenode.net. What you’ll need is an IRC client (try HydraIRC on Windows or IRSSI on Linux), and connect to the irc.freenode.net server. Once in, you might want to try joining some channels related to what you’re interested in. For example, I can be found regularly in #gentoo, #gentoo-kde, #gentoo-chat, #blenderchat, #vim, and occasionally some others depending on what I’m doing.

Set up a Personal Server

Yes, you can easily set up your own web server, even on Windows. You don’t need to be a rocket scientist. There’s this nifty little prepackaged LAMP setup (that’s Linux Apache MySQL, and PHP) in the disguised form of XAMPP. The absense of the L means it probably works on Windows, eh? The extra P is probably for Python or Perl, but I haven’t poked too much in the package to find out personally.

What use is a personal server? You can dump your files in it, give others your IP, and then they can easily download files from you. If you’re on a network (even through your router), you can easily transfer files from one computer to another at speeds reaching up to 1gb per second (either that or the little notification window lied). If you’re into webdesign, or need an environment to run PHP scripts, that’s the perfect place to do it! Or even if you want to use PHPMyAdmin (oh, the extra P could be that too) to interface with your MySQL databases (if you use them, of course) a server is probably the most useful thing you could have.

Set up some transfer protocols

We’ve all known the popular protocols, FTP, SSH, SFTP, Telnet, etc. Why don’t you set it up on your own computer? Let people upload files to your computer. Let people connect to your computer and control it remotely! If you have an X server, let people do X tunneling through SSH so from anywhere you can access your GUI applications. Or if you’re braver, setup a VNC server too so that you can control it as though you were sitting right in front of it!

You’d probably have to do some research on how to set these up for your operating system (for Linux just check your package manager), but it’s worth it. The ability to remotely access and manipulate your data from anywhere in the world is priceless. It has plenty of uses too! You can access your files from anywhere (that’s the obvious one). You can debug applications or even your failing router. You can have two people connect to one computer and run tutorial sessions, or do Extreme Programming (a style which involves two programmers working at the same time).

A word of warning though, please learn how to secure these connections, you don’t want random people poking through your stuff.

Well, that’s it for this part of the series. I realise it’s turned ever so slightly more geeky, so I promise the next part will be a lot simpler. If you aren’t of the technologically savvy type and you are reading this, you have a huge amount of research to do before you can find out how to accomplish all these things. However, repeat after me: “It’s worth it.”

No related posts.