Connecting EC2 instance using Elastic IP is not working

1. Ping to the EC2 instance. not working.

   1) check security group
   2) assign Elastic IP to the instance.

   Solution
   Add All ICMP Inbound rule in Inbound tap of Security group.

still not working. why?

2. Connecting EC2 instance using Elastic IP is not working.
   1) When running echo client-server program on same node,
      connecting to server with inet address(ifconfig) works, but Elastic IP.

   2) Connecting EC2 instance with PuTTY is working, but this program.

   Solution
   Add All TCP Inbound rule in Inbound tap of Security group.