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March 2, 2022 – 2:00 pm

Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …

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Article Archive for December 2014

Late Night Rant #24: North Korean Internet

December 22, 2014 – 8:05 pm
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Today was the day the North Koreans would have learned they had the Internet and the Americans DDOSed it. Unfortunately, they had no Internet, poor bastards. But, as long as this keeps us entertained… Hey, …

Late Night Rant #23: Kim The Sony-Slayer

December 17, 2014 – 10:09 pm
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Sony execs are shedding crocodile tears over the latest IT security breach that brought substantial financial losses to the company. Let’s not dwell on the trivial: who did it and why are irrelevant technicalities. How …

RHEL/CentOS Yum Operations

December 14, 2014 – 11:42 pm
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The Yellowdog Updater, Modified has more features than most of us will ever need. Below are some hopefully useful examples that will help keep your system maybe secure by replacing old known bugs with new …

VSFTPd, SSL, and Firewalls

December 5, 2014 – 1:58 pm
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If you ever wanted to configure SSL/TLS encryption for an FTP server behind a firewall, the “Google wisdom” ranges from “a major pain” to “can’t be done”. Fortunately, things are not all that bad. In …

Using Pflogsumm Postfix Log Analyzer

December 4, 2014 – 12:29 am
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Pflogsumm is an oldie but a goodie. It’s a Perl script that sifts through your Postfix server maillog and provides you with a neat summary of events and some statistics. This information can be useful …

Visualizing Apache Logs with Logstalgia

December 4, 2014 – 12:01 am
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The Logstalgia is a cool graphical utility for visualizing the Apache access_log files. The practical value of Logstalgia is debatable, but it’s entertainment value is not in question. The managers and NOC operators can stare …

Sending Attachments Using Mailx

December 3, 2014 – 2:32 pm
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Sometimes it’s just better to attach a file to your email than to “cat” the contents into the email body. Later versions of mailx support the “-a” option for handling attachments. With the older mailx …

Fail2ban Whitelist IPs

December 2, 2014 – 9:16 pm
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Fail2ban is an excellent security tool that will do a good job safeguarding your server. However, using fail2ban you may run into two issues: friendly fire and inability to permanently ban hostile networks. I already …

Identifying Available IPs on the Network

December 2, 2014 – 2:31 pm
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At some point available IPs on your network may become few and hard to come by. Documentation becomes outdated and does not accurately reflect which IPs are still in use. A good starting point would …