Today, i faced strange behavior by OpenDNS. When I tried to open gmail, i redirected to OpenDNS blocked page with an error “This domain is blocked. Site blocked. mail.google.com is not allowed on this network. This site was categorized in: Webmail“. I tried several times on the same machine and other machine on home network but issue remain exist.
After some googling i found that OpenDNS only block phishing and Conficker sites. Popular sites like gmail, yahoo do not block by OpenDNS. The problem is with dynamic Ip addresses. This issue appear when an IP address assigned to your network by your ISP was used by some one else. The other person using your ip address had his own filter setting in OpenDNS dashboard and he was not using some sort of IP update application. All those setting attached to that IP address now applying to your network because you are now using that IP address and those filtering and blocking settings now applying to your network.
There is simple workaround on this issue. Simply reset your modem router to get new ip address. Wait for few minutes to make sure you will get new ip address. Some times ISP assign same ip address so more time you wait less chance you will get same ip address. Now try to open Gmail it should open now. To reset ip address without switching off router or modem run following commands from command prompt. It will flush dns and renew ip address.
This can be happened with any open dns users who use dynamic ip address. It would be better if you could maintain your own account with OpenDNS account and keep your IP address upto date with IP update application