[ubuntu-cloud] Port discrepancy from Security Group specifications

Runa A. Sandvik runa at torproject.org
Mon Nov 12 19:27:56 UTC 2012

On Mon, Nov 12, 2012 at 5:19 PM, Nick Barcet <nick.barcet at canonical.com> wrote:
> On 11/11/2012 10:33 PM, Runa A. Sandvik wrote:
>> Hi,
>> The Security Group linked to my Ubuntu Precise instance (ami-ac9943c5)
>> opens ports 22 (ssh) and 443 (https). However, when I scan the server
>> for open/closed ports, I see 22 (ssh), 554 (rtsp), and 7070
>> (realserver) as open, and 443 (https) as closed. Any idea why I'm
>> seeing two additional ports that are not defined in the Security
>> Group, and why port 443 is closed?
> Where are you doing your scan from?  Another instance in the same cloud?

I scanned from my computer at home, not another cloud instance. I was
able to connect to port 554 and 7070 with telnet, but could not do
anything else. The host closed the connection shortly after.

> When you do a "netstat -aln" from your instance, do you see that it is
> listening on 443?

According to netstat, dhclient3 and sshd are the only two services
running, there are no services listening on 554/7070, and tcpdump
shows 0 packets to port 554/7070. I'm running into [1], but I have not
been able to figure out why this is happening.

[1]: http://stackoverflow.com/questions/6377686/aws-free-tier-instance-port-discrepancy-from-security-group-specifications

Runa A. Sandvik

More information about the Ubuntu-cloud mailing list