Some crazy DNS issue by My ISP

Today I faced an interesting DNS issue with my Internet Service Provider. The issue is very simple I can go online but ping request to open DNS server returns request timed out. It is very interesting, right?

The complete story is like below. While browsing I suddenly went offline and as usual to check the connectivity I ping to global DNS address. I got Request Timed Out message. So desperately I tried other open DNS addresses like 208.67.222.222 and 208.67.220.220 but they too failed to get a valid reply. Then I just ping www.google.com and it gave me to reply and my browser can go to google.com.

Screenshot of my ping operation is attached below.




After the result, I again ping 4.2.2.2 and got Request Timed Out message. Meantime I can browse to any website without any issue. I called the ISP and asked what is the actual reason for this issue. After some escalation (Normal procedure :-) )
they told me it was their server mistake and it is corrected now.

Solution to DNS issues from ISP

In case if your ISP's DNS server is not working or not up to full satisfaction we can use open DNS address on your computer. The open DNS addresses are

208.67.222.222
208.67.220.220

Steps to assign open DNS in Ubuntu Linux