kenneth $ ssh -i key.pem ubuntu@server.compute-1.amazonaws.com
OpenSSH_7.6p1, LibreSSL 2.6.2
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 48: Applying options for *
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to server.compute-1.amazonaws.com port 22.

kenneth $ telnet serverip
trying serverip...
telnet: connect to address serverip: Operation timed out
telnet: Unable to connect to remote host

kenneth $ ping serverip
PING serverip (serverip): 56 data bytes
64 bytes from serverip: icmp_seq=0 ttl=47 time=25.531 ms
64 bytes from serverip: icmp_seq=1 ttl=47 time=27.442 ms
64 bytes from serverip: icmp_seq=2 ttl=47 time=27.045 ms
64 bytes from serverip: icmp_seq=3 ttl=47 time=28.912 ms
^C
--- 35.173.139.106 ping statistics ---
4 packets transmitted, 4 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 25.531/27.233/28.912/1.204 ms

sudo launchctl stop com.openssh.sshd
sudo launchctl start com.openssh.sshd