Tuesday, September 25, 2007

How to Host a Web Server at Home With Dynamic DNS

There are a lot of moving parts to get right to do this, and not a lot of good advice about how to do it successfully. I hope that my steps will help you get it right the first time.

My need for an at home hosted web service came from trying to develop a simple FaceBook application. I needed my application hosted somewhere quick and didn't want to pay for hosting. I'm comfortable using Tomcat to host my java applications, so I decided to try to host my application at my computer at home for easier development and debugging.

The trick for hosting a site that is publicly accessible is to be able to use a non-moving target for DNS servers to resolve. Since most people don't get a static IP for home use without paying extra for it, they are stuck with a Dynamic IP address. This means that behind the scenes, you are "leasing" the IP address for a period of time, after which it is revoked and another address is assigned to you. For normal internet use, this is a seamless operation, but for web hosting we need a little help. I suggest using the free service offered by DynDNS to do hostname to Dynamic IP mapping. With their service you can create a hostname (for example, http://codebeneath.dyndns.org, a subdomain to dyndns.org) and configure that to resolve to your current IP address, which they detect for you. Or if you prefer, hit IP Chicken :)

Now, you need a way to detect when your IP address changes and automatically update your DynDNS entry. There are standalone clients that can do this, but I was lucky enough to have the capability built into my router, a LinkSys BEFSX41.

I have heard that some internet providers block port 80, so I decided just to use the default Tomcat port, which is 8080. If you stick with port 80 and run into problems, this may be the cause.

Next, we need to configure the router to forward all incoming port 8080 traffic to Tomcat. There are several ways to do this, depending on your router. The solution I don't recommend is enabling the DMZ Host setting (this is overkill and a potential security problem if you don't know what you are doing). The remaining alternatives are Port Range Forwarding and UPnP Forwarding. Port Range Forwarding is geared more for specialized internet applications such as videoconferencing or online gaming and can be used to forward an entire block of address at once.

For my case, I picked the simplest thing that worked: UPnP Forwarding. When I started, this was not the clear choice of how to do this, and many differing opinions steered me to conflicting directions. Compounding my confusion was an out-dated router firmware that provided administrative pages with different terminology and that did not even have UPnP Forwarding as an option.

I do recommend updating your router's firmware to avoid the same confusion I had and to have the latest security patches in place.

Login to your router by pointing your browser at the admin URL. For my LinkSys, the admin URL is The default username is blank (none) and the password is "admin"

If you still have your default password, change it immediately before proceeding further!

Click "Applications and Gaming" > "UPnP Fowarding".

On the first blank line enter "tomcat" as the application name, "8080" as the Ext. Port, "TCP" as the protocol to allow, "8080" as Int. Port, your internal network address (e.g. 192.168.1.xxx) and mark the Enabled checkbox. To obtain your internal network address, open a command shell and type ipconfig. A gotcha to watch out for is that your internal address may also be dynamic if your router assigns addresses via DHCP. To avoid this, you could statically configure your network devices addresses, but for my purposes DHCP was OK.

Save the router settings and close your browser.

Start Tomcat and make sure you can access http://localhost:8080. If so, then try the public address you created at DynDNS (in my case http://codebeneath.dyndns.org:8080). If all is well, you should be seeing the Tomcat welcome page! Deploy your web application and happy web hosting.

Tuesday, September 18, 2007

Thursday, September 13, 2007


What's another word for 'empowered'? I don't like it because it is overused as a corporate buzzword and under appreciated as a game-changing concept. It's the concept that I like. In your company, do you feel free to cross those invisible corporate boundaries to make things happen? To discuss, collaborate, act? I'm lucky enough to work for a company that makes me feel that way. And it's not because they make a big announcement heralding the idea to the masses: "You are empowered to make decisions".

I've heard that before and it wasn't true. There were still job titles, egos and chains of command to contended with.

'Empowered' sounds like you're being granted permission from those higher up the food chain to act. I guess the people surrounding me today, the CEO, the CIO, and my co-workers make me want to be Accountable; a concept I believe is self-granted. If I have an idea, I can own it, grow it and make it work. And not as a solo effort, either. We are encouraged to reach out and work directly with the people who can make ideas into reality.

The actions I see on a daily basis speak louder than any words to confirm this. After being hired, I met several of people in senior leadership positions in the company. As an example of their commitment to keep the communication channels open, they were adamant that there should not be an company organization chart.

Not this:

Not this



No artificial power structures in place or asking permission from the boss to talk to your peers who happen to work in a different department or on a different contract. As an organization, we are very flat, by design, and it Just Works. It's like a big tree, whose branches are weighed down by an ice storm, all suddenly shake free their icy repression and spring up to the same height as the highest branch.

Being in an environment like this has changed me. I am no longer in a cubicle reporting to a single boss. I am one of many influences in the company who increasingly don't see team boundaries, we see Singularity. We see opportunities to improve our business and our culture and we're making it happen.

This is individual accountability to own and promote ideas and to collaborate as a next generation enterprise using lightweight, online tools (including the phone!) to make it easy. This is collaborating on ideas on your corporate wiki. This is sharing your bookmarked feeds collectively through Yahoo Pipes. This is about sharing your experiences and knowledge by blogging about it. This is keeping a pulse on new technologies, not for your team, but for other teams in the company. This is a call.

This is the Manifesto that I believe in.

As Charlie says, "Advertise yourself", your knowledge and what you are passionate about, so when the time comes, people will also reach out to you to collaborate with.

Even with obstacles removed from your path, it can still be tough to follow through. I am out of my personal comfort zone on a regular basis. However, I know it's the way forward, for my company, but most importantly for me. It's my way of providing leadership at work. I can't do it with words. I have to do it by leading by example.

You can, too. Make it an infectious attitude. Lose Yourself.