Two weeks ago my DIR-825 stopped connecting to some URLs.  I made no changes to the router nor did I add any new software.  If I tether my laptop to my smartphone, I connect to those URLs without any problems.  I connected my cable modem directly to the laptop and I was able to connect to the URLs also.
I loaded the new firmware to the router and reset all the settings, but still no luck.  
Any suggestions?
Thanks.
 
Dogman