Just some basic information, in order to test NTS (Network Time Security) All what you need in order to understand how it works is here: https://blog.apnic.net/2019/11/08/network-time-security-new-ntp-authentication-mechanism/ My NTPsec server: time.signorini.ch How to install it: first remove any standard NTP or Chrony package, then get the source code and compile it: wget https://gitlab.com/NTPsec/ntpsec/-/archive/NTPsec_1_1_9/ntpsec-NTPsec_1_1_9.tar.gz tar -xf ntpsec-NTPsec_1_1_9.tar.gz cd […]
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GPS for time synchronization
GPS positioning works based on how much time the radio signal takes from the source satellite to the destination, your device. As you may know radio signals speed in the void is the speed of the light (which is also an electromagnetic wave, just at different frequencies). Speed of the light is 300’000 km/s (more […]
Continue readingMore Tagbash – PIPESTATUS and pipefail
Evaluate the exit code of an executed command is a normal practice in shell scripts, but what happens if you also want that command to pipe in another command? You lose your precious exit code. Bash provides you with the variable array PIPESTATUS, containing the exit codes along all the pipeline. But sometimes you want […]
Continue readingMore Tag“ss -i” equivalent for AIX
port=636 lsof -i:$port 2>/dev/null | awk ‘/ESTABLISHED/ && $5==”IPv4″ {print $6}’ | while read addr do echo “sockinfo $addr tcpcb”| kdb | /opt/freeware/bin/awk –non-decimal-data ‘ \ /snd_cwnd/ {print “CWND: ” (“0x”$2)+0} \ /snd_wnd./ {print “RWND: ” (“0x”$2)+0 “\nMY_RWND: ” (“0x”$4)+0} \ /snd_wnd_scale./ {print “RWND_SCALE: ” (“0x”$2)+0 “\nMY_RWND_SCALE: ” (“0x”$4)+0} \ /\s+t_flags./ {print”TCP_FLAGS: ” $0; getline; […]
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