How we ensure Cloudflare customers aren’t affected by Let’s Encrypt’s certificate chain change
Let’s Encrypt, a publicly trusted certificate authority (CA) that Cloudflare uses to issue TLS certificates, has been relying on two distinct certificate chains. One is cross-signed with IdenTrust, a globally trusted CA that has been around since 2000, and the other is Let’s Encrypt’s own root CA, ISRG Root X1. Since Let’s Encrypt launched, ISRG Root X1 has been steadily gaining its own device compatibility.
On September 30, 2024, Let’s Encrypt’s certificate chain cross-signed with IdenTrust will expire. After the cross-sign expires, servers will no longer be able to serve certificates signed by the cross-signed chain. Instead, all Let’s Encrypt certificates will use the ISRG Root X1 CA.
Most devices and browser versions released after 2016 will not experience any issues as a result of the change since the ISRG Root X1 will already be installed in those clients’ trust stores. That's because these modern browsers and operating systems were built to be agile and flexible, with upgradeable trust stores that can be updated to include new certificate authorities.
The change in the certificate chain will impact legacy devices and systems, such as devices running Android version 7.1.1 (released in 2016) or older, as those exclusively Continue reading
HN729: Open Source to Closed
With “The Cathedral and the Bazaar” as his guide, Srivats launched Ostinato, his open source project, in 2010. He needed an affordable network traffic generator at his day job, he was passionate enough to build one during his nights and weekends, and end users loved it– it has been downloaded hundreds of thousands of times.... Read more »Public Videos: Kubernetes Ingress
All the Kubernetes Ingress videos from the Kubernetes Networking Deep Dive webinar with Stuart Charlton are now public. Enjoy!
Hedge 221: Energy Aware Protocols
A lot of people are spending time thinking about how to make transport and control plane protocols more energy efficient. Is this effort worth it? What amount of power are we really like to save, and what downside potential is there in changing protocols to save energy? George Michaelson joins us from Australia to discuss energy awareness in protocols.
How Cisco sees Silicon One Easing Network Convergence and Helping with AI
With the rise of AI and its massive impact on networking, Cisco has pivoted swiftly to enable customers to utilize its converged networks to run taxing AI apps.KU053: Migrate Legacy Applications to Kubernetes with Konveyor
Whether you want to migrate legacy applications to Kubernetes in order to save the whales or for any other reason, Konveyor is here to help. Savitha Raghunathan joins us today to walk us through the open source tool. The basics: You input the application’s source code (any language that has a language server) and Konveyor... Read more »Collaborate to Trust Telco SaaS
Unlocking the full potential of telecom in the SaaS era relies on comprehensive strategies and a constant commitment to evolving security practices.LISP vs EVPN: Mobility in Campus Networks
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:
LISP vs EVPN: Mobility in Campus Networks
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:
Narrowboat: Lessons learnt
At this stage of the build internally there is only really the bedroom, snags and trims (windows, ceiling edges and doors) left to do. I am currently in Australia having a bit of RnR so this is a reflective post to show the build at its present state and go through the things I have learnt along the way. I could plan all I like but as I haven’t lived on a boat before there was always going to be a few wrong design decisions.
D2C239: “(Almost) Every Infrastructure Decision I Endorse or Regret”
You can’t just drop a knife on fish and expect there to be sushi. Jack Lindamood joins us today to share his metaphors and thoughts on picking the right IT tools and processes as outlined in his popular article, “(Almost) Every Infrastructure Decision I Endorse or Regret after 4 Years Running Infrastructure at a Startup.”... Read more »Modernizing IT Networks for Higher Education
In today’s data-driven world, higher educational institution networks and their management must be modernized to address the needs of everyone across campus. Enterprises face similar challenges and also need to modernize their networks.Stateful Firewall Cluster High Availability Theater
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.
Stateful Firewall Cluster High Availability Theater
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.
1000BASE-T Part 4 – Link Down Detection
In the previous three parts, we learned about all the interesting things that go on in the PHY with scrambling, descrambling, synchronization, auto negotiation, FEC encoding, and so on. This is all essential knowledge that we need to have to understand how the PHY can detect that a link has gone down, or is performing so badly that it doesn’t make sense to keep the link up.
What Does IEEE 802.3 1000BASE-T Say?
The function in 1000BASE-T that is responsible for monitoring the status of the link is called link monitor and is defined in 40.4.2.5. The standard does not define much on what goes on in link monitor, though. Below is an excerpt from the standard:
Link Monitor determines the status of the underlying receive channel and communicates it via the variable
link_status. Failure of the underlying receive channel typically causes the PMA’s clients to suspend normal
operation.
The Link Monitor function shall comply with the state diagram of Figure 40–17.
The state diagram (redrawn by me) is shown below:
While 1000BASE-T leaves what the PHY monitors in link monitor to the implementer, there are still some interesting variables and timers that you should be Continue reading
HS069: Regulating AI
In today’s episode Greg and Johna spar over how, when, and why to regulate AI. Does early regulation lead to bad regulation? Does late regulation lead to a situation beyond democratic control? Comparing nascent regulation efforts in the EU, UK, and US, they analyze socio-legal principles like privacy and distributed liability. Most importantly, Johna drives... Read more »