Tessera
Folgen

Chris @ Network Fun-Times

@networkfuntimes.bsky.social

Mr Nice-Posts. winner of official Most Handsome Network Engineer award 2029. JNCIE-SP, Juniper Networks instructor and courseware writer. Blogger at www.networkfuntimes.com. funny o nline man,

61 Posts582 Follower63 Folgt
Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2mo ago

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...

Enforcing the First AS in BGP AS PATHs

BGP is vulnerable to routing hijacks and path leaks that negatively impact traffic on the Internet. RPKI helps solve some of these problems, but for some forged paths, we need to rely on a simpler mec...

blog.cloudflare.com

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2mo ago

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...

Deprecated AS_SET: Why the IETF changed the rules of BGP aggregation.

RFC 9774 prohibits AS_SET in BGP. Learn why AS_SET was deprecated, its impact on RPKI and routing security, and how to migrate to compliant aggregation.

noction.com

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 5mo ago

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?

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 12mo ago

Some happy news: I passed the Japanese Language Proficiency Test (JLPT) N5 exam :) It's the beginners level cert. 800 words, 100 kanji (Chinese characters), 50 grammar points. Nothing difficult to most people - but 2nd languages do not come naturally to me, so it was a real challenge. I'm relieved!

nixCraft@cyberciti.biz · last yr.

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".

Chris @ Network Fun-Times@networkfuntimes.bsky.social · last yr.

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...

RFC 9637: Expanding the IPv6 Documentation Space

The document describes the reservation of an additional IPv6 address prefix for use in documentation. This update to RFC 3849 expands on the existing 2001:db8::/32 address block with the reservation o...

datatracker.ietf.org

Chris @ Network Fun-Times@networkfuntimes.bsky.social · last yr.

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.

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2y ago

I've been a fan of Japanese pop culture since 1995. Many half-hearted attempts along the way to learn the language. Recently started genuinely trying. Currently at the expert beginner stage, lol. I know enough to be dangerous, but no way near enough to be useful. Approx 150 kanji, 800 words.

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2y ago

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-...

How To Read A Junos Class-Of-Service Configuration

Struggling to read Junos Class-of-Service config? This post is for you: it shows you where to start, what order to read each piece in, and what to look for. After this you'll have no problem working o...

networkfuntimes.com

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2y ago

When folks talk about segment routing, it's often in regards traffic-engineered paths. Personally, I really like segment routing (specifically SR-MPLS) as an LDP replacement - which is to say, a full mesh of auto-created shortest-path LSPs, but with 100% topology coverage for backup paths.

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2y ago

Considering my follower count has risen 10x, I should probably say hi! I'm Chris. I use my website to teach networking with "jokes" and "mandatory fun". I focus on Junos/Juniper, and on service provider tech (BGP/MPLS). Here's an example post you might like: www.networkfuntimes.com/a-complete-b...

A COMPLETE BEGINNER'S GUIDE TO SUBNETTING

If you're a newcomer to networking, chances are you're struggling to get your head around subnet masks. Well don't worry: your goth uncle is here to explain how it all works. CCNA and JNCIA/JNCIS stud...

networkfuntimes.com

Chris @ Network Fun-Times@networkfuntimes.bsky.social · 2y ago

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...

My New SR-MPLS Course, and Krzysztof's SRv6 Blogs

My new four-day instructor-led SR-MPLS course is now live! In addition, my colleague Krzysztof Szarkowicz has written many free blog posts on SRv6. Click this post to find out all about it.

networkfuntimes.com