hi, i was having the same issues right now. are you a filipino too? we are also on the same ISP, smart telecommunications, i got 2 connections at home, both are running on smart. i am an IT practitioner, and i troubleshoot networks really well. and this issue isn't related to any local setup, this is most likely about DNS problem responding too long, and i have NO idea why this specially occurs on smart alone. I cant also access tumblr on my mobile using my data connection, which is also happened to be on smart. so i mark this issue related to the ISP itself. but way back months ago, i can simply access those DNS, tumblr and blogspot without having any issues. its just so happen that this newyear, i need to change my copyright2014 into 2015, im running a static html for the designs of my tumblr blog. and i cant access the site. exclusively this issue is occurring this january 2015. i cant also access subdomains (somethinglikethis.tumblr.com) or anything with .blogspot.com. i have my own .com domains for my blogs. and i can access them without having any problems. but not other blogs using the subdomains of tumblr. well, up to this point, i havent created any permanent solution for this issue. (maybe you can report in to smart) but if you really need to access or log in to those site. you can use "psiphon" its free. download, install, run. and you can go and log in to those sites without any problems. hope that would help you. there is no way this thing can be fix, without smart doing their part. i see no reason why this thing happened. it is not blocked, or filtered, the DNS simple respond too long, which is really something weird.