Found this incredible gem1 hidden in the Usage Guidelines for the OSPFv3 router-id configuration command part of the Cisco IOS IPv6 reference guide.
The whole paragraph seems hallucinated2, but that couldn’t be because the page was supposedly last updated in 2019, and LLMs weren’t good enough to write well-structured nonsense at that time:
OSPFv3 is backward-compatible with OSPF version 2.
No, it is not.
netlab does not support a Syslog server (yet), but it’s really easy to add one to your lab topology, primarily thanks to the Rsyslog team publishing a ready-to-run container. Let’s do it ;)
Rsyslog is an open-source implementation of a Syslog server (with many bells and whistles, most of which we won’t use) that can (among other things) log incoming messages to a file. Even better (for our use case), the Rsyslog team regularly publishes Rsyslog containers; we’ll use the rsyslog/rsyslog-collector container because it can “receive logs via UDP, TCP, and optionally RELP, and can send them to storage backends or files.”
How to get one when you don't have one and what happens when its gone! There is so much propaganda out there today (and I am not even referring to politics), it feels good to go back to fundamentals. Few things are more foundational to networking than Address Resolution Protocol (ARP). It is inconceivable to READ MORE
The post A Unified ARP Table (and how to get one when you don’t have one) appeared first on The Gratuitous Arp.
"Can you suggest some specs for a server for my network labs?" is probably the question I get asked the most. People reach out all the time asking for recommendations. The thing is, I never really know their exact situation or what they’re trying to do in their lab. So, I usually just share what I have and what worked best for me, and let them decide what fits their setup.
In this post, I’ll go over the cheapest way to build your own network lab without spending too much.
You don’t need expensive hardware to build a solid network lab. A used mini PC with decent specs is more than enough to run tools like Proxmox, Continue reading
I’ve previously mentioned my io-uring webserver tarweb. I’ve now added another interesting aspect to it.
As you may or may not be aware, on Linux it’s possible to send a file descriptor from one process to another over a unix domain socket. That’s actually pretty magic if you think about it.
You can also send unix credentials and SELinux security contexts, but that’s a story for another day.
I want to run some domains using my webserver “tarweb”. But not all. And I want to host them on a single IP address, on the normal HTTPS port 443.
Simple, right? Just use nginx’s proxy_pass?
Ah, but I don’t want nginx to stay in the path. After SNI (read: “browser saying which domain it wants”) has been identified I want the TCP connection to go directly from the browser to the correct backend.
I’m sure somewhere on the internet there’s already an SNI router that does this, but all the ones I found stay in line with the request path, adding a hop.
A few reasons:
This guide is the steps I follow when adding or updating NTC templates. Contributing to a project in Github is still a learning curve for me, the days of learning CLI by repetition seem long gone so when using or contributing to any of these NetOps type tools I have to keep guides as it is a bit of a struggle to remember with so many new and alien things to know and the sporadic nature that I use them.
We’re excited to announce the release of Calico v3.31, 
which brings a wave of new features and improvements.
For a quick look, here are the key updates and improvements in this release:
eBPF, automatically disables kube-proxy via kubeProxyManagement field, and adds bpfNetworkBootstrap for auto API endpoint detection.DSCP) support: prioritize traffic by marking packets (e.g., EF for VoIP).QoSPolicy API for declarative traffic control.IP-in-IP, no-encap) directly — no BIRD required!natOutgoingExclusions config for granular NAT management. Continue readingIs quantum really an immediate and dangerous threat to current cryptography systems, or are we pushing to hastily adopt new technologies we won’t necessarily need for a few more years? Should we allow the quantum pie to bake a few more years before slicing a piece and digging in? George Michaelson joins Russ and Tom to discuss.
I love well-organized small conferences, so it wasn’t hard to persuade me to have another talk at the DEEP Conference in Zadar, Croatia. This time, I talked about the role of digital twins in disaster recovery/avoidance testing. You might know my take on networking digital twins; after that, I only had enough time to focus on bandwidth and latency matter, and this is how you emulate limited bandwidth and add latency bit.