Ask the Wi-Fi Guru About the Future of Wi-Fi and Problems With WEP

By Aaron Weiss

October 07, 2010

Our monthly Q&A series offers advice to those seeking help with home or small business WLANs. This month our guru offers some insight into the future of Wi-Fi, the problem with WEP, and helps configure a wireless bridge.

Our monthly Q&A series offers advice to those seeking help with home or small business WLANs. This month our guru offers some insight into the future of Wi-Fi, the problem with WEP, and helps configure a wireless bridge.

Would you like to ask the guru a question? Write the editor.


If it seems like a year has passed since U.S. television broadcasters completed the switch to digital broadcasting, that is because it has. When the U.S. Congress set a 2009 deadline for the transition, the most visible benefit was clarity--no more analog snow, and joy--true high-definition video over-the-air. But most people already receive their television through cable or satellite, so in fact relatively few Americans were directly affected by digital broadcasting.

A second dividend from the digital transition may be much more exciting, and it is called "whitespaces". In many areas of the country, there is now a lot of unused spectrum in the range from 54-698Mhz. Previously reserved for analog broadcasting, these frequencies promise new potential in Wi-Fi technology. Last month, the U.S. FCC finalized its approval for opening up the whitespace for unlicensed wireless data networking.

The details might seem arcane, but this is a Big Deal. Today, unlicensed Wi-Fi is limited by operating at high frequencies, typically 2.4Ghz and 5.8Ghz. These signals travel relatively short distances, are often blocked by obstacles like trees and buildings, and are now quite crowded. Licensed frequencies, such as 800Mhz and 1900Mhz used by cell phone companies, travel further but are expensive to operate and therefore tied to costlier applications--just look at the price of your cellular data plan.

By opening up unlicensed lower frequencies, we could see a revolution of low-cost wireless gear with the ability to operate over much longer ranges. The first and most likely application will be covering larger spaces like campuses and business parks without the need for a network of access points. Better yet, we will hopefully see affordable broadband service extended to the vast rural areas in the U.S., which today are difficult to cover with terrestrial cables, and whose terrain blocks high frequency Wi-Fi signals.

How do I move a personal network from WEP to WPA or WPA2?

Q: Home computers, desktop and laptop. Wireless network 802.11g; security WEP. Works well and know of no problems with it. However, everything I read says WEP is not secure. Since my computer use is personal and not for business my question is: Should I change to WPA or WPA2? If so, why and how do I do it? - Dale

A: Great question Dale, because the whole question is basically a metaphor for life. There is what we know, what we don't know, and everything in between.

What we know: indeed, WEP is not secure. Due to design flaws in the protocol, data packets sent using WEP encryption can contain the keys to their own unlocking. In practice, it isn't quite that simple, but it's simple enough that a moderately knowledgeable hacker can use readily available tools to crack a WEP key in as little as a few minutes, depending on the volume of network activity they can sample.

Does that mean you shouldn't use WEP? Here the answers become murkier.

The lock on your car door isn't very secure either. A knowledgeable car thief can use readily available tools to break into your car in a matter of seconds. Still, you probably lock your car door anyway.

Both WPA and WPA2 can be compromised, but the process can be much more time consuming and isn't worth a hacker's time unless they are highly motivated. So yes, in general a WPA2 network is your safest choice in consumer-grade gear.

However, not all networking devices support WPA2, particularly older models. If your router and both your desktop and laptop wireless adapters support WPA2 then sure, you should use the best security you have readily available to you. To make the switch from WEP, you would start with your router, by opening its administration interface in a browser and configuring the wireless security settings. Exact details will vary from one model to another so you'll need to consult the manual for your router.

Once you've configured your router to use WPA2, and supplied it with a password of your choosing, your computers will automatically prompt you for this password the first time they connect to the router. Assuming they support WPA2, this is all you should need to do.

If your router or computers do not support WPA or WPA2, is it worth buying new gear to upgrade from WEP? To answer this you'll need to think about risk assessment. Are you in an apartment or highly populated environment where lots of people can see your network? One simple way to tell is to look at how many other networks you can see.

If you can see a lot of networks from your machines, it is probably worth upgrading your equipment to the best security. On the other hand, if you can't see any other networks, you probably live in a single house a good distance from neighbors. In which case, your risk factor is pretty low, and sticking with WEP is really no worse than relying on the factory door lock in your car.

Why can't I get my wireless bridge working?

Q: I just ran across your article on building a wireless bridge. However, I'm trying to use a Linksys WRT160N as the bridge to a Linksys WRT54G router. I followed your instructions up to step 4. With the newer router, the settings within the N router IP address are different, and I'm not sure what to change in order to make the "N" functional as a wireless bridge to my "G" primary router. - Seth

A: For some reason I am reminded of a certain "bridge to nowhere", which is probably not the goal here. The typical purpose of a wireless bridge is to connect wired clients to a wireless network, but based on my reading of the question, it sounds like this bridge is being built backward.

Off-the-shelf routers don't usually include the ability to act like a wireless bridge. This is because one, they are wireless broadcasters, and two, the vendors would like to sell you a separate device to build a wireless bridge. To create a bridge using a conventional router, it needs to be a router compatible with third-party firmware like DD-WRT or Tomato, which support bridge mode. You actually do have such a router, the Linksys WRT54G, but you're trying to make the WRT160N the bridge. It works the other way around.

The 160N is your primary ("vanilla") router, running stock firmware. Connect this router to your incoming broadband service. You don't really need to configure anything on the primary router to create a bridge--the magic all happens on the secondary router, in this case the WRT54G.

The linked tutorial describes using DD-WRT to create this bridge. It is important that the secondary router be assigned a LAN IP address that is compatible with the primary router. For the 160N, the default IP address is 192.168.1.1. No need to change this. You do need to change the IP address on the secondary router (the WRT54G) to something on the same subnet such as 192.168.1.2.

Hopefully this clears things up--the "N" router is not the bridge to your "G" router, it is the other way around.



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