wireless routers

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Jonathan
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wireless routers

Post by Jonathan »

Yeah, that old chestnut.

I have to replace my old router. Is there any reason not to get the Linksys WRT54G? The D-Link DGL-4300 looks nifty, but the maintaining-low-latency-for-games-even-while-downloading-files feature isn't worth the $179 price tag.

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Post by Jonathan »

http://www.wi-fi.org/OpenSection/Certif ... .asp?TID=2

Here's a nice website which will show you if a given product has been certified WPA2-compliant or not. It also gives you lists of WPA2-compliant products.

The wikipedia entry has the info on WPA2 Personal or Enterprise. Apparently, the difference is Personal you have a one-time key distribution and Enterprise you distribute new keys periodically.

http://en.wikipedia.org/wiki/Wi-Fi_Protected_Access

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Post by Jonathan »

Another thing I'm trying to evaluate is my network topology. I have two desktops in the same room, two laptops in the living room, and the cable connection in a third room. I've been sharing one wireless USB card between the two desktops, but that basically sucks. I'd like to get a ethernet bridge like the WET54G, but it costs $179, too. Plus, it's only WPA-compliant, not WPA2-compliant. The info I have says WPA2 is the full implementation of 802.11i, but doesn't mention what WPA leaves out.

Also, I wonder if the WRT54GS is worth the extra $20 over the WRT54G? Who can tell?

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Post by Jonathan »

So, USB support on the MADwifi and Prism54 Linux drivers is a WIP at the moment.

And according to this link, WPA2 requires new hardware support. That is, WPA-compliant cards can't be upgraded to WPA2-compliant through driver or firmware updates.

http://www.openxtra.co.uk/articles/wpa-vs-80211i.htm

What I need to do is cross-index the WPA2-compliance list with the Linux-compatibility list:

http://www.linux-wlan.org/docs/wlan_adapters.html.gz

This analysis reveals that there is no 802.11g WPA2 PCI card for Linux. I can find a 802.11g WPA2 Cardbus card for Linux. I can find a 802.11g WPA PCI card for Linux. Hmm.

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Post by Jason »

I have a WRT54G and it's fine. I lose connection to it all the time even though I'm at most 20 feet away at all times, but that's more due to where I live than the router. It should be fine for you though.

To evaluate network topology you're going to have draw up something like what's this page because I don't get you're layout. (MacGyver's setup on that page is pretty sweet).

If I remember correctly the difference between WPA and WPA2 is the encryption algorithm. I had to do research on wireless solutions for work like six months back so I my memory is very fuzzy. As I recall, WPA had an algorithm that had a flaw in possible key space. Rather than using the full space specified by the modulus of the key, it had the potential to repeat earlier, therefore making the key crackable within 20 minutes with 'average' packet flows and a powerful enough laptop. I think WPA2 got rid of this flaw. Of course I could be totally offbase and forgetting everything.

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Post by Jonathan »

No, that sounds about right. I'm not aware of any WPA-crackers; lord knows there are certainly plenty of WEP-crackers out there.

WPA2 uses AES according to the link. WPA uses RC4, same as WEP, but switches the keys every so often to make it tougher to crack.

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Post by Jonathan »

My network is pretty simple and doesn't require a picture.

Cable modem is in the master bedroom. The wireless router is plugged into the cable modem and is also in the master bedroom.

The laptops are wireless and are used all over the house.

The desktops are in a different room. Amber takes a very dim view of running Cat5 across our hallways. As a result, the desktops are also wireless. In practice, only one desktop is connected at a time because I only bought one desktop wireless adapter, a USB one.

I keep meaning to do something about having only one desktop connected at a time. Now we're on to hypothetical network topologies. I could connect one desktop to the other via ethernet and be done with it. Been meaning to, in fact. I could also buy a second wireless adapter, but I've been holding off on the assumption that we'd ugprade to 802.11g sooner or later. I like the idea of a ethernet bridge with at least two ports so that I don't have to fiddle with drivers, just plug the damn things in. But there aren't any ethernet bridges that support WPA2.

Brief reading suggests that the WRT54GS has Stateful Packet Inspection. Is there any functionality that I get out of that feature (i.e. don't have to manually open ports to use edonkey, etc.)?

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Post by Jonathan »

Problem solved. Amber's Intel PRO/Wireless 2100 3A supports WPA but not WPA2, so I'll run my network in WPA and get either the Netgear WG311 or the D-Link DWL-G520.

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Post by quantus »

One place I lived already had a router sharing access to every room by wire, but I wanted wireless, so I just set up wireless router with a different subnet, and went to town from there. It's really too bad that the WAN link can't be wireless, because then you could just do the same thing :-\
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Jonathan
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Post by Jonathan »

Yeah, that's what I wanted to do originally, because the router cost $59 and the bridges cost $179. I suppose I could try to accomplish that by hacking a second WRT54G, but I think I'm alright with what I got.

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Post by Jonathan »

I bought the DWL-G520. I have it working with 802.11g and WPA-PSK on my Debian sarge box. The installation was actually as painless as beta software gets.

To install the driver, I used this guy's instructions:
http://www.marlow.dk/site.php/tech/madwifi

I had already done the tough part of that, configuring the kernel, for my NVidia driver installation.

I then added these lines to my /etc/network/interfaces:

Code: Select all

auto ath0
iface ath0 inet dhcp

  pre-up /sbin/iwpriv ath0 mode 3
  wireless_essid xanadu
  wireless_channel 1
To get WPA-PSK working, I followed the directions in this FAQ:
http://www.mattfoster.clara.co.uk/madwifi-9.htm#5

The only thing I did differently was install the wpasupplicant Debian package (and the wireless-tools package) instead of building wpa_supplicant from source like the instructions do. That means I had to change this line:

Code: Select all

wpa_supplicant -Bw -d -c/etc/wpa_supplicant.conf -iath0
to this line:

Code: Select all

wpa_supplicant -Bw -d -c/etc/wpa_supplicant.conf -Dmadwifi -iath0
which I got from the help option of wpa_supplicant.

Basically, this took me an hour, which is slightly less time than it took me to get WPA-PSK working on Amber's Windows XP laptop. I definitely recommend the DWL-G520 and the madwifi driver to anyone looking for a little PCI 802.11g action under Linux.

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Post by Jonathan »

Minor update: I added the wpa_supplicant command to my /etc/network/interfaces as another pre-up line. Now the wireless connection just comes up on startup.

I was able to maintain a connection to my router for a week without any manual intervention. At the end of the week, I turned the computer off because I was leaving town, so it might have worked longer. That's longer than Amber's XP laptop can maintain a connection. I am reasonably satisfied with the performance of the madwifi driver.

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Post by Jonathan »

Jason wrote:I have a WRT54G and it's fine. I lose connection to it all the time even though I'm at most 20 feet away at all times, but that's more due to where I live than the router.
Amber had a similar problem. Turning off Wireless Zero Configuration seems to have fixed it. Perhaps it will for you, too?

http://www.ifelix.co.uk/tech/2000.html

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Post by Jason »

Dwindlehop wrote:
Jason wrote:I have a WRT54G and it's fine. I lose connection to it all the time even though I'm at most 20 feet away at all times, but that's more due to where I live than the router.
Amber had a similar problem. Turning off Wireless Zero Configuration seems to have fixed it. Perhaps it will for you, too?

http://www.ifelix.co.uk/tech/2000.html
I don't think that's the problem because whenever I lose connectivity, I usually open net stumbler to check on it. The db level drops like a rock sometime and sometimes it doesn't even sustain a constant connection. I really think someone around me is violating some FCC broadcast rules or something. I'll try this out though.

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Post by quantus »

Jason wrote:I really think someone around me is violating some FCC broadcast rules or something. I'll try this out though.
That's what happens when you live next door to spies...
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