title: AWS free-tier instance port discrepancy from Security Group specifications
body: <p>My Ubuntu Server 11.04 free-tier instance security group opens SSH, HTTP, HTTPS to the public web and nothing else (not even the inter-group TCP/UDP/ICMP ports enabled by the default sec group).</p>
  
  <p>But when I Nmap my server's public dns, it shows HTTP &amp; HTTPS closed, with ftp (21), rtsp (554), and realserver (7070) all open.  This would, of course, explain why I can't view the website I'm running on that instance, so I need to fix it.</p>
  
  <p>This is a <a href="https://forums.aws.amazon.com/thread.jspa?messageID=254870&#254870" rel="nofollow">cross-post from the AWS EC2 forum</a>, but since I've got no replies yet, I'm hoping for better luck here.</p>
  
  <p>my SecGroup (no other rules for UDP or ICMP):</p>
  
  <pre><code>TCP 
  Port (Service)  Source  Action
  22 (SSH)    0.0.0.0/0   Delete
  80 (HTTP)   0.0.0.0/0   Delete
  443 (HTTPS) 0.0.0.0/0   Delete
  </code></pre>
  
  <p>Nmap:</p>
  
  <pre><code>kurtosis@kurtosis-laptop:~/bin/AWS$ nmap ec2-184-73-70-26.compute-1.amazonaws.com
  Starting Nmap 5.00 ( http://nmap.org ) at 2011-06-14 23:27 PDT
  Interesting ports on ec2-184-73-70-26.compute-1.amazonaws.com (184.73.70.26):
  Not shown: 994 filtered ports
  PORT STATE SERVICE
  21/tcp open ftp
  22/tcp open ssh
  80/tcp closed http
  443/tcp closed https
  554/tcp open rtsp
  7070/tcp open realserver
  
  Nmap done: 1 IP address (1 host up) scanned in 8.52 seconds
  </code></pre>
  
  <p>Why are http and https closed when my security group specifies they should be open, and why is ftp, rtsp, and realserver open when my security group does not include them at all? Anyone know why the discrepancy?</p>