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

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Archive for the ‘IPv4’ Category

Some posts on example domains and example IP-ranges (IPv4 and IPv6)

Posted by jpluimers on 2025/05/05

Here are some of my blog posts on documenting using example domains and example IP-addresses or IP-ranges:

(I really wish that example.org and others would service SMTP with blackhole routing so one can also use it for bogus email addresses in documentation)

The blog posts above were incomplete (IPv6 was missing; IPv4 was not explained), so below are more links that do a better job based on a Tweet from [Wayback/Archive] Julia Evans (@b0rk).

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Posted in Conference Topics, Conferences, Development, DNS, documentation, Event, Infrastructure, Internet, IPv4, IPv6, Power User, Software Development | Leave a Comment »

IPv4 subnet/CIDR table from OccupytheWeb on Twitter: “Network Basics for Hackers: Subnetting, Subnet Masks and CIDR Notation …”

Posted by jpluimers on 2024/11/27

I wrote about programs and scripts doing IPv4 subnet calculation, but sometimes it is easier to have a table at hand, so here is the one I found at [Wayback/Archive] OccupytheWeb on Twitter: “Network Basics for Hackers: Subnetting, Subnet Masks and CIDR Notation #networks #networkbasics #subnetting #infosec #networks4hackers #cyberwarrior #cyberwarrior #networkbasics #networkbasics subnet”

Notes:

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Posted in Development, Hardware, Internet, IPv4, Network-and-equipment, Power User, Scripting, Software Development | Tagged: , , , , , | Leave a Comment »

Guess the maximum DNS Response Size… (by Jan Schaumann)

Posted by jpluimers on 2023/12/26

Every once in a while Jan Schaumann writes a long Twitter thread and saves it in a blog post. Always good ways to learn. This time it was no different: [Wayback/Archive] DNS Response Size started with

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Posted in Communications Development, Development, DNS, Internet, Internet protocol suite, IPv4, IPv6, Power User, TCP, tcpdump, UDP, Wireshark | Leave a Comment »

IPv4 to IPv6 conversion on a load balancer causing rare packet loss

Posted by jpluimers on 2018/11/02

Nice find on not so nice packet conversion: [WayBack] Fun with IPv6 We were investigating packet loss. The loss rate was very low (smaller than 1 of 1000) but as UDP was used, it caused rare but noticeab… – Martin Seeger – Google+

Basically the load balancer could not cope well converting empty IPv4 UDP checksums to IPv6 and back.

Or like Kris mentioned it: [WayBack] Null. In Zahlen: -1., causing a nice set of comments to be posted on short term solutions versus long time forgotten problems.

–jeroen

Posted in Internet, IPv4, IPv6, Network-and-equipment, Power User, routers | Leave a Comment »