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 […]
Continue readingMore TagGPS 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 TagOPNsense – create pftable for google networks
I tried in several way to enable firewall rules to google addresses like smtp, apis, captcha and so on. In OPNsense you can add an host alias inserting the FQDN instead of the IP address. Then you can schedule a reload of the alias every 5 minutes or so. Most of the times it works […]
Continue readingMore TagGet rid of bufferbloat with SQM
Let’s start from a bit far…TCP/IP works so well, since decades ago, with links in the order of kbits/s, until nowadays with 10Gbits/s and more. Of course there’s been some modifications since the beginnings, but the concept is the same, and almost unchanged. The fact is there’s no way for an endpoint to know the […]
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 TagOpenWRT – reload conf when RADAR is detected
OpenWRT is a Linux operating system targeting embedded devices, main targets are Wireless Routers, like the name suggests ( https://openwrt.org/ ). The first issue I had was with the configuration of the 5GHz channel, so I want to share this. Use of radio frequencies is strictly regulated, every county has its own law, but usually […]
Continue readingMore TagSnooker – Fastest 147 in history
The ten commandments
The planet is fine, the PEOPLE are fucked!
“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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