Use netcat instead of telnet
Network engineers often use telnet to establish a connection to a service on a remote server. Apple dropped the telnet and ftp client in macOS High Sierra. First I was…
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Use netcat instead of telnet
Authenticate sudo with TouchID on a MacBook Pro
If you own a Mac equipped with a touch bar and you use the command line and sudo often, you can enable the TouchID of your Mac to authenticate yourself.…
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Authenticate sudo with TouchID on a MacBook Pro
Hide your version of BIND
To hide your version of bind, enter the following value to your named.conf version "[NONE]"; in the option section: options { directory "/var/lib/bind"; version "[NONE]"; }; Check the value with…
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Hide your version of BIND
Subnet Masks
A subnetwork, or subnet, is a logically visible, distinctly addressed part of a single Internet Protocol network. The process of subnetting is the division of a computer network into groups of computers that have a common,…
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Subnet Masks
SI prefixes
An SI ⇒prefix is a name that precedes a basic unit of measure to indicate a ⇒decimal ⇒multiple or ⇒fraction of the unit. Each prefix has a unique symbol that is prepended to…
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SI prefixes
pcap filter
tcpdump and ngrep are both based on libpcap. Therefore both use the same filter expressions. Here is the manual page of the ⇒pcap filter expression. These filter expressions are also…
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pcap filter