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Ever since I installed DD-WRT (v24-sp2 08/07/10 std-usb-ftp) on my router (RT-N16), my browsing got substantially slower. Using FirePHP I figured out that it's being caused by VERY long DNS lookups (~30 seconds). When the domain name was very recently accessed then speed is very good.

I tried changing DNS on the computer and I tried messing around with the options on DD-WRT. I have tried to configure the router with Google DNS and/or OpenDNS. My current DNS output after using ipconfig -all is:

Can someone help me debug and solve this problem? I'd like to snoop the requests themselves. How can I know which DNS requests are being sent and which are failing/succeeding?

Note: I don't expect this to be relevant but my router is connected to the internet through an ONT.

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up vote 0 down vote accepted

Try rebooting the ONT, power down the router, unplug power cord to the ONT, then remove the cover of the inside ONT and disconnect one lead of the battery backup, leave it disconnected for 15 minutes.

Connect AC power back to the ONT and then connect the battery, power up the router.

Sounds like flaky firmware upgrade, try flashing it again or another version.

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Hmm... Not solved but improved... now I'm only having issues on my desktop... Could be something related to the PC or the fact it's the only PC connected through Ethernet to the router. Your help was useful so I'll accept the answer. Thanks. – Nuno Cordeiro Jun 4 '12 at 22:48

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