The Power of Linux

I just wrapped up a consulting engagement up here in New York and I had a great opportunity to highlight the power of Linux to my client.

The Problem

Their email server was having trouble sending email for some reason and we were trying to rule out the firewall that I had just installed for them. The firewall (Check Point, of course) was reporting that the email system was sending RST packets to the remote mail server, which it was reporting as a state issue and subsequently dropping the traffic. I confirmed this with tcpdump.

The client wanted to know if it was the firewall or the mail server, i.e. they were still concerned it was the firewall. I tried to explain that it was the firewall doing the dropping, but only because the mail server wasn’t operating correctly. As for why it wasn’t I could feign no hypothesis; the email server in question was Novell GroupWise (shudder).

Linux To The Rescue

The next thought in my mind was to show him what a normally functioning mail server looks like. In no more than 20 seconds I had a fully functioning installation of Postfix running, and pulled my Blackberry from its holster.

I then simply echo’d test, piped it to mail, and sent it to my personal email address:

echo test | mail -s Test daniel@dmiessler.com

I then quickly pressed the up arrow and enter like 10 times — launching 10 perfectly formatted email messages out of their network.

Roughly five (5) seconds later I heard the beautiful sonar ping sound of incoming mail on my Blackberry. 10 of them. My client just watched as they hit the screen, and when I showed him the 10 green outbound SMTP entries in Check Point (a stark contrast to the alternating green-red on the Groupwise box) he knew the problem was on his own email server.

Bottom line — I needed a fully functional email server to test outbound SMTP. 20 seconds later, thanks to apt-get install postfix, I had that test server and I was able to move along in the problem-solving process.

Case in point — Linux owns. And for those that care, score one for Ubuntu/Debian too. In cases like these, apt > portage without a doubt.