Where are you getting this error?
When are you getting this error?
Does the network block requests from your area?
You're connecting FROM India, but where are you connecting to?
Do you manage the network? If not, do you have support available?
Do you collect syslog events that you can look at?
Is it an authentication failure or another failure?
Is there Posture Assessments being done? If so, what are they?
Do the logs from monitoring / collection nodes (MNT, CAM/CAS, ETC) show a reason for failure?
Typically this would be something that starts at a Tier I support level and works its way up the chain from there. There are just so many possibilities from the data that you gave us, and so much being left out it's impossible to begin to ascertain what could be amiss.
