Applications

Monitoring (featured logo)

Install nfdump and nfsen netflow tools in Linux

Using nfsen it is possible to view IP traffic statistics on Linux interfaces including the graphs showing data sent and received (see the screenshot to the right) as well as historical information about all data transfers. So after you’ve configured nfsen and nfdump to monitor… Read More »Install nfdump and nfsen netflow tools in Linux

Sendmail for virtual users with procmail, spamassassin and dovecot

Today I’d like to describe setup of sendmail that allows to establish receiving of e-mails for certain domain and sort incoming messages between virtual users. Those users must be able to fetch received e-mails via POP3 or IMAP protocols with or without TLS encryption. The… Read More »Sendmail for virtual users with procmail, spamassassin and dovecot

Cisco (featured logo)

How to monitor traffic at Cisco router using Linux (Netflow)

By default Cisco IOS doesn’t provide any traffic monitoring tools like iftop or iptraff available in Linux. While there are lots of proprietary solutions for this purpose including Cisco Netflow Collection, you are free to choose nfdump and nfsen open source software to monitor traffic… Read More »How to monitor traffic at Cisco router using Linux (Netflow)

Ubuntu (featured logo)

youtube-dl: download youtube videos in Ubuntu using command line

If you use Ubuntu (or other Linux distribution) and you wish to download some video from youtube.com into .flv file you can try using youtube-dl command line utility. It just downloads videos without any online applications, converters or etc. Type the following command in terminal… Read More »youtube-dl: download youtube videos in Ubuntu using command line

Create Encrypted Filesystem Within a File (truecrypt way)

Some time ago I’ve written an article named 16 GB encrypted candy file describing how to create encrypted filesystem within regular file. After quick research it became clear that cryptoloop is vulnerable and there is open exploit available on the web: see it here (thanks to everybody who commented that article). So I don’t recommend to use cryptoloop but instead take a look at truecrypt that makes it possible not only to encrypt whole storage but also to create encrypted file just like I’ve described in 16 GB encrypted candy file article.

Read More »Create Encrypted Filesystem Within a File (truecrypt way)