I am trying to configure my linksys BEFW11S4 router to an att Motorola modem using an IMac OSX10.6.8 operating system. I followed all the router instructions, all the lights are on, my ethernet and airport lights are green, but I can't connect to the internet. I configured the router PPoE with my att name and password, and also tried used the DHCP setting, but I still have the same problem. I also can't seem to make my IMac preferences save a password for my network name.
Is this a new installation, one where these two devices have never been configured together successfully, or a configuration that was working previously and somehow became un-configured?
To be perfectly honest, that router is ancient! It's only supports wireless B and the thoroughly hacked WEP protocol. It's so old it wouldn't surprise me if perhaps the PPPoE support is outdated as well (unless you know for a fact the two do work together from prior experience w/ them).
So even if you got it to work, what would be the point? Your wireless network will never be secure, not unless you have no intention to use wireless. And even then, firewalls have improved significantly since the BEFW11S4 was released (circa 2002), including SPI (stateful packet inspection), fixes to known vulnerabilities, protection against DOS (denial of service) attacks, etc.
There just comes a point when it’s time to move on, and considering you can grab a modern wireless N router for as a little as $15-20 these days (I even know of one for $10 after rebate at the moment), it just doesn’t make sense. As I said, your current problems might very well be the fact it’s so old.