3. Review the information in the Description tab. In this example, both settings are enabled.
DNS resolution Enabled
DNS hostnames Enabled
4. To update these settings, choose Actions and either Edit DNS Resolution or Edit DNS Hostnames. In the dialog box that opens, choose Yes or No, and then choose Save.
5. Now you can wait for few minutes and check, issue will be resolved.
Note: You may also try restarting the rpcbind and nfs service in the EC2 instance.
# service rpcbind restart
# service nfs restart