today since i didn't have anything to do i wanted to give a second try to the tomato firmware on my asus rt n66u, everything went fine during the installation process, but like on my first attempt when i try to connect and access the internet it simply doesn't work, only thing that works is pinging the router ip. My configuration is pretty basic, i have a adsl modem that is connected to the wan port of the router, only wireless and no lan and i didn't change any setting except for the wpa2-personal aes protection. Checking from the web gui everything seems fine, the router even gets an wan ip address from dhcp but there's no internet, the strange thing is that if i move the cable from the wan to one of the lan ports it works.
I seriously don't know what to do, i spent almost two days seraching for a solution but i couldn't find it.
If someone could help me it would be much appreciated.
P.S. I don't really know which informations you need to understand my situation, so please if you need to know something tell me.
Under Advanced - Conntrack / Netfilter, scroll to the bottom of the page. You will find the option to increment the TTL. Set if for +5 and see if it fixes the internet. Be sure to reboot and obtain a fresh IP address after adjusting TTL.
When the router has obtained an IP address from the cable modem, use the "Tools" - "Ping" test utility in the router to ping 22.214.171.124 and see if you get responses. If you do then ping google.com to be sure the address resolves and that you get responses. If you do then repeat these two tests from the computer that is connected to the router.
Using the ping utility in the router, ping the GATEWAY IP address that the router WAN received via DHCP from the DSL modem. If the router cannot ping the gateway that was just handed to it then you need to perform a full NVram clear.
I can ping the gateway ip from the wan. Thant's one of the few things i can do really.
EDIT: Now it works… i changed the wan from dhcp to ppoe. The problem now is that i don't know why it works( even if i thing that depends on my old modem), also is there any benefit from using dhcp instead of ppoe?
Your DSL modem uses PPPoe with the service provider. Your router does not use PPPoe to communicate with the modem. Your entire problem was simply that you were making incorrect assumptions. That is why they invented help forums. Glad you got her working !