Chris @ Network Fun-Times

#Wireshark 4.6.9 has been released. Cheers! These releases are brought to you by the Wireshark Foundation. If you or your employer can donate, it would help us out immensely. www.wireshark.org/docs/relnote... wiresharkfoundation.org/donate/

Random historical MPLS thing I learned today, surprised I hadn't seen mentioned before: there was once an attempt to make a version of LDP that could do constraint-based traffic engineering. datatracker.ietf.org/doc/rfc3212/ Wikipedia says the IETF stopped progressing it in 2003 in favour of RSVP.

Another outstanding blog by my guy Bryton Herdes and his colleagues at Cloudflare (Iliana Xygkou and Mingwei Zhang) on a new-ish feature called BGP roles. By explicitly defining who is a customer, peer, and provider, route leaks can be caught and ignored early. blog.cloudflare.com/rfc9234-bgp-...

Anyone know why RFC number 10000 was skipped? Is it still to come? Will it be a good one? Shall we have a house party for the big day when it goes live? We should have a house party for the big day when it goes live.

Outstanding blog by Cloudflare (co-written by the excellent Bryton Herdes) on how BGP prefixes can be hijacked using peers that don't check that the first AS is also the AS advertising the prefix to that peer. The internet was architected in a more trusting era! blog.cloudflare.com/enforce-firs...

Great write up of a 2025 RFC that totally deprecates the BGP AS_SET path segment type. Explains what it is, why it causes security problems, and the ways that its removal enables RPKI on the entire AS_PATH. Interesting stuff. www.noction.com/blog/depreca...

Pals, I'm looking at a Wireshark RSVP packet capture. I cannot for the life of me work out how to show the token bucket rate/size in decimal , rather than scientific notation. Does anyone know please?

An IS-IS question for anyone who knows. Did pre-2005 network OSs let you turn off L1 and L2 hellos per-interface? Or were you limited only to turning off a level on the entire node? If it was possible per-interface, was the option always there from day one of IS-IS support? Or was it added later?

Super interesting video about how the Japanese internet was started "illegally" in the 1980s, and some ways it had an influence on today's global internet. www.youtube.com/watch?v=kAjd...

Lol - I enjoyed this closing paragraph on Ivan Pepelnjak's post on reaching off-subnet nodes in IP and CLNP, talking about historical "hacks" for IPv4 hosts to auto-discover routers on a LAN: blog.ipspace.net/2025/03/comp...

I wasn't able to attend this conference, but I'm excited to watch some of these videos. Lots of great topics on offer. Take a look:

I see 1000028 IPv4 prefixes. This is 240 more prefixes than 6 hours ago and 970 more than a week ago. 61.78% of prefixes are /24.

It's a few years old, but I just discovered a super cool set of gacha (Japanese capsule toys) for a miniature rack of routers and switches. A forum user called "Agg" has posted extensive photos. Well worth a look: forums.overclockers.com.au/threads/mini...

Packets that don't receive a reply to ping comnand aren't truly lost; they briefly enter a low-latency parallel dimension where time flows differently. Occasionally a stray "lost" packet will reappear days or even weeks later. This phenomenon is known as the "Lost Packet Dimension".

I love every video Cathode Ray Dude makes. His most recent one is of great interest to network engineers. He tells the history of 80s and 90s internet connectivity, exploring ISDN, leased lines, and the advent of ADSL. www.youtube.com/watch?v=ympj...

In addition to the famous 2001:db8::/32, Today I learned that there's now a second IPv6 prefix that is reserved for documentation: 3fff::/20. Lol, I'm only seven months late to the party on this one! datatracker.ietf.org/doc/html/rfc...

Oh my, this is brilliant - someone edited an orchestra to make it sound like they’re doing a live performance of a dial-up connection. If the comments are to be trusted, it's accurate! youtu.be/wuN-bW_zS0Q?...

When you study a new skill like network engineering, as you move onto the advanced pieces, you might find you forget the basics - because you're not thinking about them as much. This is normal. You're not stupid. You're not doomed to fail. There's a lot to remember, and it's all part of the journey.

I received a lovely email today from someone who discovered my blog post on Class of Service (aka QoS) in Junos, and said it helped them understand the config. Well, I'll definitely use that as a chance to share the post again! Hopefully it'll help you too: www.networkfuntimes.com/how-to-read-...

KRAZAM is back with another brilliant sketch. This time: artisanal data collectors. www.youtube.com/watch?v=eDr6... It's joyous nonsense. Once you're done, check out their sketch "IETF Celebrates The Standards". Easily one of my favourite things on this otherwise-cursed internet. Absurd genius.

Nobody Ikes CAPTCHAs so thanks to Guillermo Rauch, who created a Doom classic video game based one where once you kill 3 monsters you are human. doom-captcha.vercel.app

For New York mag, I wrote about the slop economy nymag.com/intelligence...

The IETF working group for IPv6 maintenance is called 6man. Despite my repeated emails, they REFUSE to acknowledge whether 6man is related to Five Guys. Reader, I promise you: I will not let them dodge this question.

NEW POST: After many months of work, my four-day instructor-led SR-MPLS course is now live! Plus, Krzysztof Szarkowicz has written some great blogs introducing SRv6. Want to find out more? Clicky-click: www.networkfuntimes.com/my-new-sr-mp...

Musk is a thieving little shit. Automatically signing everyone up to the "steal my work" setting, not notifying users, and hiding the opt-out so you can't even do it on the app.

Jeff and Drew! What a combo. I extremely highly recommend that you sign up to this.

"Fun" game: If you ever study SR, look out for the phrase "Segment Routing leverages the source routing paradigm". It's the first sentence of many RFCs—and it also appears in *tons* of vendor docs, blogs, training, etc. One person wrote it, and countless many others have copy-pasted it exactly.

Today I polished up my two-part intro to MPLS segment routing. I added some new facts, corrected some mistakes, and made it a little bit tighter. If you're curious about SR-MPLS, now is a very fine time to give it a read! Here's Part 1: www.networkfuntimes.com/mpls-segment...

At the request of no-one, I have joined yet another hell website. Did you know that there are more IPv6 addresses than there are people in Chicago? It's true! Try counting them if you don't believe me. Follow me for more networking facts. Or, don't. Your poor choices are your own to make.