Setting up a router using the DD-WRT firmware.

[Oooska]

I picked up a WRT54GL a week or so back after someone recommended I pick one up instead of picking up a PCI wifi card and external antenna to pick up a relatively week wireless connection.

A bit of background info: I live in a park of apartments owned by my university. They came up with the ingenius idea to install wireless APs through the park, so residents could pick up a wireless connection in their apartments and they wouldn't need to run ethernet through all the buildings. Great, right? Yeah, except they ran out of money in this project and the APs are not powerful enough to penetrate into the apartments and give a strong signal. So this is where the DD-WRT enabled router comes in.

I don't have a whole lot of experience with wireless network, outside of setting up small home networks in the past. I messed with the DD-WRT firmware a bit, and have successfully bridged the network to one of the wireless APs in the apartment complex. Only real problem with that is I'm fairly certain they don't want me doing that because they have no control over my router if it decides to go a bit batshit crazy. I'm willing to do it if its my only option, though I can only get 10mbps (if even that) when transferring files from my computer to another through the access point. I'd like to setup the router to essentially be like any home router, but instead of using the WAN port to get its Internet connection, it'll use the AP signal I set.

I'm not sure if I'm being entirely clear, and I'm definitely not sure if what I want to do is even possible. I'm not really sure what I should be looking at settings wise to do this, assuming it is possible. If I need to clarify what I'm trying to do further, I'd gladly do so.

 

[Vertigo Acid]

Having run a pair of WRT54G with DD-WRT firmware in the past, let me share my experiences:
Here is how I would configure that router in your situation

1. Setup in bridged mode. This is really the only way to do it, as the linksys routers don't seem to support AP Client mode (a feature of a lot of standalone access points). You can't setup anything more fancy like WDS, because you don't own the other router.
2. Go into the VLAN configuration and set the WAN port on your router to be on the same VLAN as your LAN ports. You now have a 5-port switch instead of a 4-port
3. Head over to the advanced options, and crack up your transmit power. 100mw seems to be a nice level before the router starts to have overheating problems
4. If you're only getting 10mbit, that's just how good of a signal you are getting. You can try getting the high-gain add-on antennas from linksys. One thing that i've seen work well is building a parabolic-style reflector out of aluminum foil to put behind your router, opposite the AP you are connecting to. You are trying to make your omnidirectional router into as directional of a device as possible. Hooking up cantenna or other yagi-type anntenas to get a better signal is also a a possibility.
5. If you plan on doing any bittorrent or other filesharing, make sure you have the maximum number of concurrent connections set, and a lower than normal timeout. These routers don't play very nice with those protocols until you do that
6. Setup a nightly reboot. This does wonders for stability in the long-run
7. I'm assuming you are, but just in case, make sure you have the latest (v23 IIRC) DD-WRT firmware, as lots of very good things happened since v22.
8. Make sure you're not configured to allow access to the admin interface from the outside world. Change the default passwords.
9. Set your DHCP lease to 9999 minutes (0 will not work, and it will drop your connection each time that lease expires. annoying as hell).

 

[Oooska]

Thanks for all the tips. I plan to get around to setting it up tonight.
I do have one question though--you said not to allow the outside world access to the routuer, however I've found no way to actually access the router directly when its in bridged mode, unless I enable access to it from the outside world, since thats essentially where my Internet connection is coming from. . . is there another way of accessing the router that I missed?

 

[Vertigo Acid]

Nope, not that i'm aware of, was just a suggestion to not enable remote management

 

[0ldman]

I'd go a lot simpler.

Unless you want wireless access for another PC, just set the WRT54G in client mode, the radio is the client, gives out DHCP address through the LAN ports, may need to change your internal IP addressing, depending on the school's config, but otherwise...

The way Vertigo Acid recommended sounds like its for an old version of DD-WRT.

If you want wireless access repeated in the apartment, Vertigo's method is more along the lines of that.

As for rebooting nightly, I've set up a couple of bridges, mesh networks, etc, I use keep alive to ping the other AP and reboot if there is no reply. I've had setups running for months on end (thunderstorms, so power isn't on for months on end) with no reboots.