Forcing apt-get to use IPv4

When or if you run into trouble with apt-get and IPv6 connections timing out or not resolving properly at all, it may be a good idea to simply prevent apt-get from using IPv6. Use -o Acquire::ForceIPv4=true when running apt-get, or create /etc/apt/apt.conf.d/99force-ipv4 and put Acquire::ForceIPv4 …

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Using nmap to “ping” remote ports

nmap -p 443 nmap -p 21,22,2222,80,443 nmap -p 50-100 nmap is a very versatile tool for analyzing remote hosts. Given the above examples, nmap will return the scanned ports’ status as open, closed, filtered, and so on.

Using MTR to create a text file report

mtr –report –report-cycles 20 > ignetrpt.txt The above should be entered on one line. Using MTR this way makes it easy to simply send a trace report via e-mail. It can also be used in an automated way to generate a report e-mail when …

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