It has been a constant problem not only for me but for a lot of people as well. There are times when I get reports that people cannot see any of my blogs or some other people’s sites I host. Yet, the server is up, there is no problem on the data center and the affected sites load fine from other locations or other ISPs.
Almost all local ISPs have this problem — poor DNS architecture, network congestion, or inadequate peering arrangements — PLDT (esp. Smart Wifi), Eastern Telecoms, Globe Quest (Innove), and GreenDot.
What I usually suggest to people is to reset their modem and reboot. If you’re on a corporate account, it’s also effective to call the ISP’s tech support and ask them to hook you to a different/better DNS server. I do get a lot of arguments with their tech guys thru email exchanges and even if they fixed the problem, they wouldn’t admit the issue originated from their end.
Then, here comes OpenDNS:
Two things make OpenDNS faster than similar services. First, Open DNS runs a really big, smart cache, so every OpenDNS user benefits from the activities of the broader OpenDNS user base. Second, OpenDNS runs a high-performance network which is geographically distributed (see network map) and serviced by several redundant connections. OpenDNS responds to your query from the nearest location. That means we’re very fast (and extremely reliable, to boot).
Instead of using your default DNS settings, you can use OpenDNS instead. Been using it for a couple of days now and seemed to work fine and somewhat faster.
Here are instructions on how to use it with your PC (if you connect directly to the net) or configuring your routers (e.g. Linksys). Try it and see if you’re still having problems with not being able to view certain sites. Hopefully, it does solve the problem.