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Archive for the ‘Power User’ Category

Most network protocols are TCP based, so be aware ping uses ICMP and traceroute UDP

Posted by jpluimers on 2021/09/08

Interesting thread: [WayBack] SwiftOnSecurity sur Twitter : “I had this issue in my prev company network. QoS will drop ICMP and you’ll chase your tail. If you want to find out if a network service works, test the service. If you want to know if TCP works, use TCP.… “

So:

tcpping and tcptraceroute for the win!
remember that some protocols, rely on ICMP or UDP, so ensure these work on your network tool (do not QoC them away!)

[WayBack] Zimmie on Twitter: “It is perhaps worth noting: traceroute does not generally use ICMP. Instead, it uses this horrific UDP port range with a different port for every probe at every hop. 30 hops? That’s 90 different UDP ports you just tried. Makes its value questionable at the best of times.…”

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, Power User, TCP, UDP | Leave a Comment »

Tricks used by software developers to https://127.0.0.1

Posted by jpluimers on 2021/09/07

Long interesting thread at [WayBack] Thread by @sleevi_: “@SwiftOnSecurity So, some history: It used to be folks would get certs for “localhost”, just like they would from “webmail”, despite no CA e […]”

In 2019, applications were still using tricks (including shipping private keys!) to “securely” access https://127.0.0.1 on some port.

This should have stopped in 2015, but hadn’t. I wonder how bad it still is today.

[WayBack] SwiftOnSecurity on Twitter: “Me: Threat-hunting rare DNS lookups in a corporate network. Confluence: … “

[WayBack] Tavis Ormandy on Twitter: “This turned out to be a real vulnerability! 😮 The certificate was issued by @digicert, who are now required to revoke it. It was issued before mandatory CT, so didn’t show up in …. See … for context.…”
[WayBack] Ryan Sleevi on Twitter: “So, some history: It used to be folks would get certs for “localhost”, just like they would from “webmail”, despite no CA ever having validated the name. They just relied on pinky promises to be good. Luckily, browsers forbid that … “
[WayBack] Ryan Sleevi on Twitter: “Look at the dates on those. Yes, it’s a things CAs used to do, and they had to be dragged kicking and screaming into not doing it (and even then, *many* ignored/“oopsied” the requirement to revoke). I regret to inform you it didn’t stop until 2015/2016 – … “
[WayBack] Guidance on Internal Names – CAB Forum
[Archive.is] HTTPS encryption on the web – Google Transparency Report: atlassian-domain-for-localhost-connections-only.com
[Archive.is] HTTPS encryption on the web – Google Transparency Report
- SubjectC=AU, O=Atlassian Pty Ltd, L=Sydney, ST=New South Wales, CN=atlassian-domain-for-localhost-connections-only.com
- Serial NumberA:3E:93:53:0E:74:53:AE:CB:40:BA:20:10:12:F8:FB
- IssuerC=US, O=DigiCert Inc, OU=www.digicert.com, CN=DigiCert SHA2 High Assurance Server CAValidity11 May 2017 — 15 May 2020
The domain is (at the time of writing, so hopefully that is now “was”) used by the [WayBack] Administering the Atlassian Companion App – Atlassian Documentation
- [WayBack] Companion App doesnt work in corporate network.

At the time of writing, the interactive Google DNS showed the domain pointing to localhost [WayBack] Google Public DNS:

Result for atlassian-domain-for-localhost-connections-only.com/A with DNSSEC validation:

{
  "Status": 0,
  "TC": false,
  "RD": true,
  "RA": true,
  "AD": false,
  "CD": false,
  "Question": [
    {
      "name": "atlassian-domain-for-localhost-connections-only.com.",
      "type": 1
    }
  ],
  "Answer": [
    {
      "name": "atlassian-domain-for-localhost-connections-only.com.",
      "type": 1,
      "TTL": 1620,
      "data": "127.0.0.1"
    }
  ]
}

[Archive.is/WayBack] SSL Server Test: atlassian-domain-for-localhost-connections-only.com (Powered by Qualys SSL Labs)

Assessment failed: IP address is from private address space (RFC 1918)

Read the rest of this entry »

Posted in Communications Development, Development, DNS, HTTP, Internet, Power User, Software Development, TCP, TLS | Leave a Comment »

Indeterminate Form Infinity Times Zero – YouTube

Posted by jpluimers on 2021/09/06

Infinity is not a number and you cannot do arithmetic with it. This means that in mathematics, in contrast to what some people believe, infinity times zero might not equal to zero.

As infinity as mind boggling to most, two interesting videos below.

The first about infinity times zero, the second about some interesting paradoxes around infinity.

But first a few other links:

Read the rest of this entry »

Posted in Mathematics, Power User, science | Leave a Comment »

Actuele spoorkaart Nederland

Posted by jpluimers on 2021/09/06

[WayBack] Actuele spoorkaart Nederland:

Visualisatie van de treinenloop in Nederland op basis van actuele reisinformatie.

Dit is waar http://kubus.mailspool.nl/spoorkaart/ heen verhuisde: https://spoorkaart.mwnn.nl/

Deze zijn dus hopeloos verouderd:

Via [WayBack] Robert van den Brink on Twitter: “Haha dacht dat jij nogal zelfredzaam was, maar zie bijv. [spoorkaart] voor de series die wel rijden. Op Hvs-Ut rijdt bijv. een (extra) IC 28600 heen en weer.… “

–jeroen

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Posted in LifeHacker, Power User | Leave a Comment »

D10U003 Dell OptiPlex 3060 Micro documentation links

Posted by jpluimers on 2021/09/06

For my link archive [WayBack] Support for OptiPlex 3060 | Documentation | Dell US linking to these D10U003 Micro specific documents:

[WayBack] optiplex-3060-desktop_white-papers4_en-us.pdf: Statement of Volatility
[WayBack] optiplex-3060-desktop_users-guide3_en-us.pdf: dust filter
- [WayBack] Dell OptiPlex Micro Dust Filter User Guide
[WayBack] optiplex-3060-desktop_users-guide5_en-us.pdf: cable cover
- [WayBack] Dell OptiPlex Micro Cable Cover User Guide
[WayBack] optiplex-3060-desktop_owners-manual5_en-us.pdf: Service Manual
- [WayBack] Dell OptiPlex 3060 Micro Service Manual
[WayBack] optiplex-3060-desktop_owners-manual6_en-us.pdf: Setup and specifications guide
[WayBack] optiplex-3060-desktop_service-manual7_en-us.pdf: Setup and specifications guide
- [WayBack] Dell OptiPlex 3060 Micro Setup and specifications guide
[WayBack] dell optiplex 3060 micro form factor,d10u,d10u003,dell regulatory and environmental datasheet.pdf
[WayBack] dell optiplex 3060 micro form factor d10u d10u003 dell regulatory and environmental datasheet.pdf
[WayBack] dell optiplex 3060 micro form factor d10u d10u003 european union – declaration of conformity.pdf
[WayBack] dell optiplex 3060 micro form factor d10u d10u003 ukrainian – declaration of conformity.pdf
[WayBack] dell optiplex 3060 micro,d10u,d10u003,european union – ce declaration of conformity.pdf

Via Google: [WayBack] optiplex-3060-desktop_specifications3_en-us.pdf

––jeroen

Posted in Hardware, Power User | Leave a Comment »

Worlds Smartest Chessboard | Square Off

Posted by jpluimers on 2021/09/03

Cool “gadget”: [WayBack] Worlds Smartest Chessboard | Square Off:

Experience the future of chess with a telerobotic chessboard that would make a worthy gift for anyone!

If you get one, the largest version:

allows to move pieces from the side back to their correct place on the board
live stream via the app ([Archive.is] Square Off – Apps on Google Play or [Archive.is] ‎Square Off Chess on the App Store)

Nice video demonstrating it is below.

–jeroen

Read the rest of this entry »

Posted in Fun, Hardware, Power User | Leave a Comment »

Multiple commands in one sudo: use “sudo sh -c ‘apt update && apt upgrade -y'”

Posted by jpluimers on 2021/09/03

So I won’t forget: [WayBack] @nixcraft on Twitter: Instead of typing the following on your Ubuntu/Debian/Mint Linux desktop: sudo apt update sudo apt upgrade -y Do to save typing and time at the CLI (add to your shell startup): alias update=”sudo sh -c ‘apt update && apt upgrade -y'” See for more info:

[WayBack] How to run multiple commands in sudo under Linux or Unix – nixCraft:
sudo syntax to run multiple commands

The syntax is:
sudo sh -c 'command1 && command2' sudo -- sh -c 'command1 && command2' sudo -u userNameHere -- sh -c 'command1; command2' sudo -- sh -c 'command1; command2' sudo -- bash -c 'command1; command2' sudo -i -- 'command1; command2; command3' sudo -i -- sh -c 'command1 && command2 && command3'

…

UNDERSTANDING SUDO COMMAND OPTIONS

-- : A — signals the end of options and disables further option processing for sudo command.

sh -c : Run sh shell with given commands

'apt-get update && sudo apt-get -y upgrade' First update repo and apply upgrades if update was successful.

…

A note about using sudo command in a shell script

Here is a sample shell script that shows how to use or run multiple commands with sudo:
#!/bin/bash
echo "Running commands as a root user..."
sudo -- -sh -c <<EOF
apt-get update
apt-get -y upgrade
apt-get -y install nginx 
apt-get -y remove nano
apt-get clean
echo "All done."
EOF
A note about using sudo with bash shell aliases

The syntax is as follows for shell aliases:
alias foo="sudo -- sh -c 'cmd1 && cmd2'"
alias bar='sudo -- sh -c "cmd1 && cmd2"'

–jeroen

Posted in *nix, *nix-tools, bash, Power User | Leave a Comment »

For my link archive: DNS over https

Posted by jpluimers on 2021/09/02

DNS over HTTPS

For my link archive:

DNS over HTTPS – Wikipedia / Public recursive name server – Wikipedia
[WayBack] RFC 8484 – DNS Queries over HTTPS (DoH)
- [WayBack] DNS Queries over HTTPS
- [WayBack] GitHub – dohwg/draft-ietf-doh-dns-over-https: Discussion of draft-ietf-doh-dns-over-https in the IETF’s DOH Working Group
[WayBack] DNS over HTTPS · curl/curl Wiki · GitHub (which has a list of publicly available servers)
[WayBack] A cartoon intro to DNS over HTTPS – Mozilla Hacks – the Web developer blog
[WayBack] DNS over HTTPS – Cloudflare Resolver

JSON DNS output

Some DNS over HTTSP providers support dns-json, which Cloudflare delivers non-pretty printed.

Read the rest of this entry »

Posted in Cloud, Cloudflare, Communications Development, Development, DNS, Encryption, HTTP, https, HTTPS/TLS security, Infrastructure, Internet, Internet protocol suite, Power User, Security, Software Development, TCP, TLS | Leave a Comment »

comex: “Hiding video streams inside PNGs uploaded to Google Drive … How does it get the browser to skip the PNG header”

Posted by jpluimers on 2021/09/02

Wondering what people now are using to store video uploads on cheap and fast network sites: [WayBack] comex on Twitter: “Hiding video streams inside PNGs uploaded to Google Drive: https://t.co/rmK8jicJYl (But what does the m3u8 look like? How does it get the browser to skip the PNG header?)” explained the 2019 situation:

[Archive.is] Deep dive into the world of illegal streaming – Laurent Meyer – Medium

[WayBack] hls.js demo

[WayBack] GR3YH4TT3R on Twitter: “They don’t use “browsers”, they use specialized resolvers that google breaks on a semi regular basis and the m3u8 typically looks something like this, … “

[WayBack] GitHub – grafov/m3u8: Parser and generator of M3U8-playlists for Apple HLS. Library for Go language.

[WayBack] m3u8/sample-playlists at master · grafov/m3u8 · GitHub

–jeroen

Read the rest of this entry »

Posted in Development, Media, Media Streaming, Power User, Software Development, Video | Leave a Comment »

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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Power User’ Category

Most network protocols are TCP based, so be aware ping uses ICMP and traceroute UDP

Tricks used by software developers to https://127.0.0.1

Result for atlassian-domain-for-localhost-connections-only.com/A with DNSSEC validation:

Indeterminate Form Infinity Times Zero – YouTube

Actuele spoorkaart Nederland

D10U003 Dell OptiPlex 3060 Micro documentation links

Worlds Smartest Chessboard | Square Off

Multiple commands in one sudo: use “sudo sh -c ‘apt update && apt upgrade -y'”

sudo syntax to run multiple commands

UNDERSTANDING SUDO COMMAND OPTIONS

A note about using sudo command in a shell script

A note about using sudo with bash shell aliases

For my link archive: DNS over https

DNS over HTTPS

JSON DNS output

comex: “Hiding video streams inside PNGs uploaded to Google Drive … How does it get the browser to skip the PNG header”

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archives

Recent Comments

Recent Posts

Blog Stats

Meta title

Tag Cloud Title

Top Clicks

Top Posts

My badges

My Flickr Stream

Pages

All categories

Email Subscription

Archive for the ‘Power User’ Category

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Result for atlassian-domain-for-localhost-connections-only.com/A with DNSSEC validation:

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sudo syntax to run multiple commands

UNDERSTANDING SUDO COMMAND OPTIONS

A note about using sudo command in a shell script

A note about using sudo with bash shell aliases

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DNS over HTTPS

JSON DNS output

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