My Openshift cluster is unable to resolve host github private repository during build

Getting error as below while trying to build image using private github repository.

Cloning "[email protected]:XYZ/repo.git" ...
WARNING: timed out waiting for git server, will wait 1m4s
error: ssh: Could not resolve hostname Name or service not known
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Please note- I am running my Openshift cluster over VM, and over VM git server is resolved sucessfully.

Any kind of help/idea behind it would be appreciable.
Thanks in Advance.

Source: Docker Questions