I am a Network Admin from India, managing a large University Network of more than 15000 users.

Here goes my problem - >

My DNS is unable to get ip address for ns1.p34.dynect.net. when i use dig +trace twitter.com on my DNS Server i get this messages:-

dig: couldn't get address for 'ns1.p34.dynect.net': failure

and this is happening with all those sites listed with dynect.net like twitter,linkedin,quora etc.

Find the attached screen shot for the same message.

Right now I have temporally fixed (not actually fixed) the problem using Google DNS (8.8.8.8)

What could be the issue as It is able to resolve all other sites perfectlly.

Thanks

Edit:

As suggested in answer, I am attaching one more screen shot.