Hey Furry Nutz,
I forgot to mention that I did try disconnecting everything from the router and just plunging in one pc to a lan port to troubleshoot.
As for the rest:
01- Cable service
02- Stand alone modem
03- Sorry, forgot to post this: RCA Cable Modem Model DHG534B
04-My modem doesn't have a built in router, so that's not really an option.
As for the things to try->
01- QoS (I didn't have gamefuel option), advanced dns services and DNS relay were all off when I was troubleshooting and I'm pretty sure they were off before the problem hit.
02-I tried reserving a DHCP adress (assigning an ip to the MAC of the ethernet card on my pc). Though it worked perfectly without DHCP reservations for two years.
03-I tried setting up my pc to auto detect the ip as well as manually inputing it (192.168.0.1 for gateway, I never changed the default address), and assigning my ip to 192.168.0.x (X means I tried various combinations of the range I knew DHCP was supposed to be giving out), subnet mask to 255.255.255.0
04-I remember that SPI was set to Port and Address Restricted for TCP and UDP before the problem hit. But I think that it might have switched to it's default setting when I reset the router
05-upNp was enabled before and after though I don't remember if Multi-cast streaming was on or off... I think I always left it in it's default setting.
06- All unnecessary devices where not present during troubleshooting (only pc and router where on and connected to each other).
07- All cables are working fine. Though they are pretty old (and long), I've been using them for probably 8+ years, but I'm using them right now to send this message as well as doing everything else I do online. I don't notice too much lag either in regular browsing or even gaming.
AT any rate, there is one important factor to consider. The router WAS working for about 2 years with absolutely no problem, connected to other 2 routers. This went on fine until suddenly last week my DIR-615 kept reseting and giving me a hell of time to access its control panel. Eventually I just gave, I simply can't get into it's control panel.
The same applied to my late DIR 600, for the first few days it also worked fine, and then suddenly stopped working (when I say suddenly I mean, that nothing was done to the router, I had it password protected with a password generated in keypass, theoretically only I was able to access it's control panel). Wireless was set to WPA2 AES, and was (as far as I know) used by ppl around here and the odd guest that would need internet access.
As for someone reseting it without me knowing... very unlikely as the ppl around here are extremely non tech-savvy.
I mean, I really don't know why all of a sudden, after all this time it would just stop working, and if that weren't enough a few days after I got a new one to replace it, it too stopped working "out of the blue".
Ohh as for a potential electrical problem: I had the router behind an APC passive surge protector. The cable that connects my modem to the outside is also plugged into this filter, so both electric and internet cables are filtered.
Anyhow, if it where an electrical problem I think my modem would have fried to, as it's also connected to the filter my old d-links were connected to. (Also if it where an electrical surge or something, the router's lights wouldn't even blink right?)