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Article Title: Linksys WRT54GS as a wired Router, and Network Address Translation

Article Author: Daryl Quenet
Article Category: Hardware Related
Times Read: 9639
Date: 2005-12-26 21:03:35
Pages: 1

Any network administrator worth a grain of salt will stress the importance of a router / firewall solution, regardless of network size. With the recent influx of Viruses, it has never been a better time to invest in a router. One of the main advantages of running a router is something called Network Address Translation (NAT). NAT allows you to supply network connectivity to an entire network with a single IP (Internet Protocol) address. It does this by using reserved internet addresses, that have been set aside for just this reason. The most popular addresses used in NATs are the 10.x.x.x, and 192.168.x.x IP address ranges.

If you have just a singular computer, you may think this is unnecessary. Well think again, this solution even has advantages for users like you. By assigning your router a real IP, the router assigns your computer a NAT IP address. Now whenever someone out on the internet tries to scan your computer for security holes, they will only see the router. This means that even if your Windows is not fully up to date (which is not recommended!), your computer will be safe from the outside world. Monthly new virus variants are created that will scan out vulnerable windows installations based on IP address ranges. Now when one of these worms scans all it sees is your router, not your vulnerable windows installation.

Up until recently I was running a Linksys BEFSR41, which is a 4 port wired router. My biggest beef with this router was that when I was downloading off the internet I was being throttled by the router. My home connection is the Shaw Extreme package, and in my area I can sustain 822Kb/s. However with the Linksys BEFSR41 router in place I was effectively being throttled down to 540Kb/s, and even then the speed were not consistent constantly dipping below 300Kb/s. Two things contributed to this:

The router only has a 10Mbit WAN (Wide Area Network) port for connecting to the modem.
The router was just down right slow, it was never intended for high speed communications.

After reading up on the Linksys WRT54GS Wireless Router specifications I knew this would be my solution. Unlike the previous generation Linksys WRT54G router this one had several improvements geared at users who do large network transfers. The main selling points that got me was the 8Mb Flash and 32Mb of RAM, and the 10/100 WAN port. Now there have been several revisions to the Linksys WRT54GS, the version that I purchased was the V2.1 revision. Unfortunately they don't mark the hardware versions on the package, just on the sticker on the bottom of the router. There has only been one subsequent hardware revision which is V.4.

Now down to the exciting part, so I took this little baby home hoping it would solve my router blues. The first thing I did was power it up and surfed over to the Linksys website, to download the latest firmware. The firmware process is painless as Updating the firmware is one of the options within the router configuration. To access the configuration in a web browser type http://192.168.1.1, from one of the computers that is connected to the unit. If at first it doesn't connect go into the cmd prompt and enter ipconfig /release, then ipconfig /renew (Windows 2K / XP / XP64 / 2K3). The default password is admin / admin.

The second thing I did after installing the firmware was to assign my host as the DMZ host. For the average user this is not advisable as you lose most of the router protective functions. When you set a DMZ host this makes your machine appear to be the router. So if the router receives a request (ie a scan) that has no particular NAT destination it will be routed to that computer. This is handy if you remote controller your machine, or run multiple system services. Like wise if you are running services on your machine(s) you can setup forwarding rules based on ports, this is the recommended approach.

The third step I did was to ensure that the wireless section of the route was encrypted. You would be surprised at how many people forget to setup WAP or any other protection on their Wireless Routers. This very phenomenon has lead to something called War Driving, which is the art of driving around in your car roaming for wide open networks. Although this may be an offence, it doesn't deter a lot of people from stealing internet services. This may be especially bad if you live within an apartment where multiple people could potential steal your connectivity, and even run up bandwidth charges, or end you up in court for alleged copyright infractions.

Once everything was in place it was time to stress test the router. To do this I fired up my favourite newsgroup client and downloaded multiple gigabytes of data. Unlike my previous Linksys BEFSR41 router, the Linksys WRT54GS was able to sustain a solid 822Kb/s from the news server. Not only that I have noticed a substantial latency decrease when doing remote connectivity to my Windows desktop with UltraVNC. Although I have yet to use the Wireless section of this router I can easily give it five stars for a consumer based wired router product.

A note for the geeks out there that love Linux, this router is based on Linux. You will also be amazed at the amount of options in the firmware, right down to custom routing entries. Another interesting fact about this router is that there is a community based on writing their own Linux distributions for these routers to enable even more advanced features. However this is unadvisable as it will void your warranty, and may turn your router into a pretty paper weight.

You can definitely look forward to reviews of the wireless capabilities of this router next month!