Linux Blog

Linux For Everyone!

Filed under: General Linux — TheLinuxBlog.com at 12:12 am on Friday, January 30, 2009

Today, while I was in the shower I was thinking:

“What way do people closely interact with Linux everyday without even knowing it”


With the recent re-regurgitation of the old GNU vs. Cisco case it came to mind that many people use Linux on a daily basis by using their routers. While this is not the best example of Linux in its prime it is a good way to demonstrate the versatility of the Linux operating system. To some, the concept of an operating system running on anything other than the latest and greatest hardware is alien. To Linux users this is part of its beauty.

I personally have two Linux powered routers. The first is a cheapo Belkin that is not very well suited, the second is the better supported WRT54G.

There are many variants of the WRT’s My personal favorite is DD-WRT because this is what I’ve used for a while, and I’m most familiar with it. I have an office with quite a lot of equipment that is somewhat distant from my cable modem and access point. What I use the first router for is a static access point, next to the cable modem, the second router has been re-purposed to be a full time bridge. I encrypted the communications and set up some static IP’s. I have a hundred or so DHCP lease IP’s available for friends and virtual machines. Whats great about this setup is DD-WRT does a great job as a bridge and hardly ever drops. My cable connection has gone out far more times then the bridge, if it ever has at all. I am able to connect many machines to the Internet over wireless while keeping my office communications switched. I do not have any of the hassles of multiple wireless cards with touchy Windows and Linux drivers and random dropped connections. The wireless bridge is so reliable I am able to do VOIP over it, with QoS to ensure that my calls always have priority over streaming media and other network traffic. DD-WRT truly has been the best thing that I’ve ever done to my routers and is really a great replacement for the Linksys junkware.

With this in mind next time your dearest Windows zealot complains about the stability of their Small/Home Office router, perhaps taking a stab at the stability of Linux (if their router even runs it) how about you educate them on the versatility of Linux. If you like, you could walk them through the very easy steps of installing a WRT variant onto the router (if possible) and enable Linux’s full potential to shine through.

Getting Home

Filed under: General Linux — TheLinuxBlog.com at 6:30 am on Friday, January 16, 2009

Getting into your home network from the wild west known as the internet can be a pain, especially if your IP address is always changing on you, or perhaps the one time that you need to get into your home network your IP address changed.

This happened to me not so long ago, my IP address hardly ever changes but my IP address did happen to change when I moved into my new residence. Assuming that my address would stay the same I headed off to work, unfortunately I was unable to phone home.

Many people know about the free sites that let you update your IP address such as DynDNS, no-ip.org etc. But I couldn’t settle for that mediocre domain. By setting up a CNAME in my DNS I was able to forward a subdomain to my dynamic update address which in effect allowed me to remember home.mydomainname.com rather than the wacky no-ip.org address I chose. You can do the same using free utilities, providing that you have a little time and some control over your DNS.

Before you proceed make sure you have a way of setting a CNAME for your domain name. You can try your domain registrant if you use their web servers, maybe your web host gives you the ability to manage zones and if not ask them if they can add it for you, most times they will.

You will need to set up an account with one of the free providers I used No-IP.com but others like DynDNS.org, freedns.afraid.org, ZoneEdit.com and easyDNS.com should work.

Once you have set up an account with them and have your IP address mapped to a domain name, go ahead and add the CNAME record into your DNS.

The next step is to install and configure the program, script, cron or whatever method your free DNS account uses to update. I used my DD-WRT installation and plugged my account information into the DDNS tab, I checked the update and it registered my IP.

Once you have got your IP address into the free DNS provider, you should check to make sure that it works by doing a lookup on that host name. Use nslookup to do this:

nslookup yoursubdomian.your-free-dns-account.com

If it resolves to your home IP address, then your set to move forward with tackling the task of adding the CNAME into the DNS for your domain name. I cannot cover how to do this with every system in this article but basically you create a zone with the domain, 14400 IN CNAME and the full address of your free DNS with a period at the end. This is important or your name will not resolve properly.

Depending on what DNS servers you use it may take a while for the DNS to get updated. In nslookup I set my server to use OpenDNS’s in to test to make sure the name resolved properly. To do this, start nslookup and type:

> server 208.67.222.222

Once you perform a lookup on your new subdomain, you should see something like the following:

> home.yourdomainname.com

Server: 208.67.222.222

Address: 208.67.222.222#53

Non-authoritative answer:

home.yourdomainname.com canonical name = yoursubdomain.your-free-dns-account.com

Name: yoursubdomain.your-free-dns-account.com

Address: <your IP>

Thats all there is to it. If your IP is updating via your free DNS service and you set up your CNAME then you will be able to find your home, or give your home address to anyone wishing connect without the embarrassment or hassle of explaining your subdomain and free domain account.

Some notes on DD-WRT

Filed under: General Linux,Linux Hardware,Linux Software — TheLinuxBlog.com at 1:44 am on Saturday, June 21, 2008

For those of you that don’t know DD-WRT is a modified version of firmware somewhat like that of the Linksys NSLU2 except more geared towards wireless routers, it runs on over 80 models.

I needed to finally set my home office / desk up with my home wireless network. I currently have a Belkin running DD-WRT and was very happy with the versatility. I have temporarily used it as a wireless bridge in other applications, so I thought I’d add another DD-WRT box to my network and use it as a bridge as I had previously done.

As noted above DD-WRT does support a large variety of wireless routers, the problem is finding a supported model. I purchased another cheap Belkin as it was on the known working hardware and came to realize that it was not possible to get DD-WRT set up on it. It was an version that was specifically put on the not supported list which I had failed to check.

A lot of Netgear routers are supported, but be careful. I noticed that the Model numbers do work, but the newer Netgear versions of the same model are not supported. I oped to buy a WRT54G for a modest $49.99. It has slightly less ram, and flash memory meaning that it can not support the full version but it has more then enough features in the micro version that it can run.

The Linksys WRT54GL retails about $65-$90 and can be purchased from most computer stores that have a decent selection. It features some pretty good specs, like the WRT54GS except it has more RAM and more flash. Again, this depends on the version you get. If you purchase the WRT54GL you are guaranteed to get a working version of DD-WRT on it though. It took me a while to find my WRT54G, I shopped at Best Buy, Circuit City, Office Max, Staples and they all had the “latest and greatest” models that are not yet supported by DD-WRT and were incredibly over priced. At one point I was very desperate and almost purchased an overpriced WAP54G which is the same thing without the built in switch. I am very happy that I didn’t as I would have also had to wire up my 16 port switch to a power supply since it went bad.

If your considering purchasing a router to run DD-WRT just check the black list first and take a print out of the supported and not supported lists from DD-WRT.com (The employees of big box retail stores don’t like it when you take every model they have to a computer with Internet and compare the models / versions one by one only to take them all back.)

Linux Wireless Morals

Filed under: General Linux — TheLinuxBlog.com at 2:40 pm on Monday, April 7, 2008

Is it moral for some one who uses Linux to borrow some ones Wireless?

Lets say you are at a hot spot and you need to jump online really quickly but some the internet house your are at charges for wireless. Is it moral to connect to some one else’s wifi?

Maybe you just moved and the internet has not arrived at your house yet. Is it moral to use a neighbors for an undefined amount of time before you are settled in and have the internet set up?

If you answered yes to any of these questions then you may either be cheap (like me) or have low morals. Either way, there are ways to protect your identity and information while borrowing wireless by using Linux.

A good way to protect your self while borrowing some one else’s wireless is to tunnel with SSH. You can use a squid proxy on a port and set up your SSH to forward a local port to the squid server. Once this is done your unencrypted http traffic is now tunneled through an encrypted SSH session. If the person who owns the wireless network (or any one else) were to sniff the packets they would just see the destination address and not the full traffic information.

Use SSH for everything that is unencrypted. SSH to a known host and use these protocols here. FTP and POP are good examples of protocols that can be used by SSH. Don’t use an instant messenger through the internet, it is very easy to sniff the packets. Some times a friend may give out incriminating information which could get you in trouble.

A good device to help with protecting your information while using some one else’s wireless is DD-WRT. Once installed on a supported device it has many functions that can be used. Bridging mode, VPN passthru, advanced routing can all be used to protect your information. DD-WRT would be especially good if set up as a bridge to the other persons wireless. You could use a NAT firewall to hid how many devices you really have connected and change the mac addresses of the clients.

In the future I’ll be showing you more ways to hide your privacy while using wireless technologies so stay tuned!