The firewall on your AP is by no means sufficient, what might be, is if it has the capability for IP filtering, that firewall is only for the WAN access on the router (assuming it has a WAN point) the wireless users hitting your AP will be seen as LAN , so the firewall will not block their requests, but an IPfilter will .
you will be amazed at what you can do with an underpowered PC, NO MONEY, some nix distro's (no big L [8D]), and absolutely minimal knowledge , perhaps a little ability to use web consoles, I'll refer you to Smoothwall, or mon0wall for starters, I highly recomend monowall, anyone checked it out yet?? its not as well publicised as smoothwall. Currently, its only lack is uPNP, but provides lots of other functionality, which smoothwall only provides in its corporate package (band throttling etc).
Loosecannon, I'd like to get my hands on this highly acclaimed cannonball and give it a go, I'll drop you a mail sometime when things calm down in my life a little, to discuss if you're open to share your lifes work with me!
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Just looked at the spec of you router, in addition to the standard firewall, "For added management, the router also has a full-featured Access Control option.This integrated feature allows you to filter traffic through your network based on IP address or MAC Address"
I was just browsing around my EL-Cheapo AP/router etc, and I was amazed to discover, it also has a feature, where u simply check the iP's that you want to allow Gateway routing.
Allow LAN access by:
ALL Wireless stations
Selected Wireless stations only
Allow Internet access by:
ALL Wireless stations
Selected Wireless stations only
These things are getting so easy to use, and incorporating great features!! So glad I wasn't born 20 years earlier, life must have been tough back then. LOL!