One of my readers sent me an interesting update on the post-QUIC round of NBAR whack-a-mole (TL&DR: everything is better with Bluetooth AI): Cloudflare (and the other hyperscalers) are full into QUIC, as it gives them lots of E2E control, taking a lot of choice away from the service providers on how they handle traffic and congestion. It is quite well outlined by Geoff Huston in an APNIC podcast. So far, so good. However, whenever there’s a change, there’s an opportunity for marketing FUD, coming from the usual direction. Read more ..read more

Yesterday, I had an Intro to netlab presentation at the wonderful RIPE SEE meeting in Athens. The presentation is already online; I will update this blog post once the recordings are published ..read more

Another lovely must-read rant from the cranky security professional. TL&DR: Data protection requirements like PCI-DSS aren’t there to make companies more secure but to make it too expensive for them to hoard excessive customer data (see also: GDPR ..read more

TL&DR: FRRouting advertises the IP prefix on the lo loopback interface with zero cost. Let’s start with the background story. When we added FRRouting containers support to netlab, someone decided to use lo0 as the loopback interface name. That device doesn’t exist in a typical Linux container, but it’s not hard to add it: $ ip link add lo0 type dummy $ ip link set dev lo0 up Read more ..read more

One of my friends is running a large IPv6 network and has already experienced a shortage of IPv6 neighbor cache on some of his switches. Digging deeper into the root causes, he discovered: In my larger environments, I see significant neighbor table cache entries, especially on network segments with hosts that make many long-term connections. These hosts have 10 to 20 addresses that maintain state over days or weeks to accomplish their processes. What’s going on? A perfect storm of numerous unrelated annoyances: Read more ..read more

Lasse Haugen had enough of the never-ending “we can’t possibly deploy IPv6” excuses and decided to start the IPv6 Shame-as-a-Service website, documenting top websites that still don’t offer IPv6 connectivity. His list includes well-known entries like twitter.com, azure.com, and github.com plus a few unexpected ones. I find cloudflare.net not having an AAAA DNS record truly hilarious. Someone within the company that flawlessly provided my website with IPv6 connectivity for years obviously still has some reservations about their own dogfood ..read more

All the Kubernetes Ingress videos from the Kubernetes Networking Deep Dive webinar with Stuart Charlton are now public. Enjoy! Explore ..read more

I decided not to get involved in the EVPN-versus-LISP debates anymore; I’d written everything I had to say about LISP. However, I still get annoyed when experienced networking engineers fall for marketing gimmicks disguised as technical arguments. Here’s a recent one: Read more ..read more

Dmitry Perets wrote an excellent description of how typical firewall cluster solutions implement control-plane high availability, in particular, the routing protocol Graceful Restart feature (slightly edited): Most of the HA clustering solutions for stateful firewalls that I know implement a single-brain model, where the entire cluster is seen by the outside network as a single node. The node that is currently primary runs the control plane (hence, I call it single-brain). Sessions and the forwarding plane are synchronized between the nodes. Read more ..read more

A long-time friend sent me this question: I would like your advice or a reference to a security framework I must consider when building a green field backbone in SR/MPLS. Before going into the details, keep in mind that the core SR/MPLS functionality is not much different than the traditional MPLS: Read more ..read more