RedHat6.4のバグだそうで。
Was able to fix this. This is due to a bug from REDHAT for 6.4 rhel instances[https://bugzilla.redhat.com/show_bug.cgi?id=956531]. After launching the machine from an AMI. Connect to the machine and switch to root user and make below changes to /etc/rc.d/rc.local file …
Remove the following three lines and save the file:
cat <> /etc/ssh/sshd_config UseDNS no PermitRootLogin without-password ../ One should also remove garbage entries from /etc/ssh/sshd_config file .. The machine once rebooted after these changes works fine.
Thanks Ashwani