Underscores (in Hostnames) Strike Again
I don’t know why I decided to allow underscores in netlab node names. Maybe it’s a leftover from the ancient days when some network devices refused to accept hyphens in hostnames, or perhaps it’s a programmer’s subconscious hatred of hyphens in identifiers (no programming language I’m aware of allows them for a very good reason).
Regardless, you can use underscores in netlab node names (and plugins like multilab use them to create unique hostnames), and they work great on Linux distributions we recommend… until they don’t.
What follows is a story about the weird dependencies that might bite you if you ignore ancient RFCs.
Otak Anda, Atlet Tersembunyi: Mengungkap Rahasia Neuro-Olahraga yang Jarang Dibahas
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Ketika kita membicarakan olahraga, fokus kita seringkali tertuju pada otot yang kuat, teknik yang sempurna, atau strategi brilian di lapangan. Kita memuja atlet karena fisik mereka yang menakjubkan. Tapi, pernahkah terbersit di benak Anda, apa sebenarnya yang membedakan seorang atlet elit dengan mereka yang hanya “baik”? Jawabannya mungkin bukan terletak di otot mereka, melainkan di dalam organ yang paling kompleks di tubuh: otak.
Selamat datang di dunia Neuro-Olahraga, sebuah bidang yang masih tergolong baru namun revolusioner. Ini adalah ilmu yang mempelajari koneksi langsung antara sistem saraf, fungsi kognitif, dan performa fisik. Artikel ini akan mengajak Anda melampaui pembahasan “fokus” atau “konsentrasi” yang klise, dan menyelami mekanisme otak yang sesungguhnya bekerja di balik setiap gerakan presisi, setiap keputusan sepersekian detik, dan setiap momen “keajaiban” dalam olahraga.
Apa Itu Neuro-Olahraga? Lebih dari Sekadar Mental Blocking
Neuro-olahraga bukanlah psikologi Continue reading
Hedge 290: The Amoeba and the Mathematician
In this Hedge roundtable, Eyvonne, Tom, and Russ discuss The Amoeba and the Mathematician
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TNO052: Internet History with Len Bosack
Len Bosack, co-founder of Cisco Systems and the CEO of XKL, sits down for a discussion with Scott Robohn. Len shares how he went from a mathematician to being responsible for pioneering the widespread commercialization of LAN technology. We also get to hear his firsthand account of building the first multi-protocol routers at Stanford and... Read more »HN808: Is IT a Young Person’s Game?
Is the ideal IT employee just leaving college or a veteran with years of experience? Russ White joins Ethan Banks and Drew Conry-Murray to discuss the complexities of this question. Younger professionals just out of college are more willing to work longer hours or unpopular shifts, learn new tools and skills, and take risks. Older... Read more »Lab: Multilevel IS-IS Deployments
Like OSPF, IS-IS was designed when router memory was measured in megabytes and clock speeds in megahertz. Not surprisingly, it includes a scalability mechanism similar to OSPF areas. An IS-IS router could be a level-1 router (having in-area prefixes and a default route), a level-2 router (knowing just inter-area prefixes), or a level-1-2 router (equivalent to OSPF ABR).
Even though multilevel IS-IS is rarely used today, it always makes sense to understand how things work, and the Multilevel IS-IS Deployments lab exercise created by Dan Partelly gives you a perfect starting point.
Click here to start the lab in your browser using GitHub Codespaces (or set up your own lab infrastructure). After starting the lab environment, change the directory to advanced/1-multilevel and execute netlab up.
An In-Depth Look at Istio Ambient Mode with Calico
The Next Step Toward a Unified Kubernetes Platform: Istio Ambient Mode
Organizations are struggling with rising operational complexity, fragmented tools, and inconsistent security enforcement as Kubernetes becomes the foundation for modern application platforms. As a result of this complexity and fragmentation, platform teams are increasingly burdened by the need to stitch together separate solutions for networking, network security, and observability. This fragmentation also creates higher operating costs, security gaps, inefficient troubleshooting, and an elevated risk of outages in mission-critical environments. The challenge is even greater for companies running multiple Kubernetes distributions, as relying on each platform’s unique and often incompatible networking stack can lead to significant vendor lock-in and operational overhead.
The Tigera Unified Strategy: Addressing Fragmentation
Tigera’s unified platform strategy is designed to address these challenges by providing a single solution that brings together all the essential Kubernetes networking and security capabilities enterprises need, that includes Istio Ambient Mode, delivered consistently across every Kubernetes distribution.
Istio Ambient Mode brings sidecarless service-mesh functionality that includes authentication, authorization, encryption, L4/L7 traffic controls, and deep application-level (L7) observability directly into the unified Calico platform. By including Istio Ambient Mode with Calico and making it easy to install and manage with the Tigera Continue reading
React2Shell and related RSC vulnerabilities threat brief: early exploitation activity and threat actor techniques
On December 3, 2025, immediately following the public disclosure of the critical, maximum-severity React2Shell vulnerability (CVE-2025-55182), the Cloudforce One Threat Intelligence team began monitoring for early signs of exploitation. Within hours, we observed scanning and active exploitation attempts, including traffic originating from infrastructure associated with Asian-nexus threat groups.
Early activity indicates that threat actors quickly integrated this vulnerability into their scanning and reconnaissance routines. We observed systematic probing of exposed systems, testing for the flaw at scale, and incorporating it into broader sweeps of Internet‑facing assets. The identified behavior reveals the actors relied on a combination of tools, such as standard vulnerability scanners and publicly accessible Internet asset discovery platforms, to find potentially vulnerable React Server Components (RSC) deployments exposed to the Internet.
Patterns in observed threat activity also suggest that the actors focused on identifying specific application metadata — such as icon hashes, SSL certificate details, or geographic region identifiers — to refine their candidate target lists before attempting exploitation.
In addition to React2Shell, two additional vulnerabilities affecting specific RSC implementations were disclosed: CVE-2025-55183 and CVE-2025-55184. Both vulnerabilities, while distinct from React2Shell, also relate to RSC payload handling and Server Function semantics, and are described in more detail Continue reading
LIU005: The Importance of Community In a Networking Career
AJ Murray joins Kevin and Alexis to share his unique journey into tech, pivoting away from aviation maintenance into networking. Together they explore the importance of person-to-person networking and building a community in order to be successful. They also talk about the reality of burnout, which ultimately led AJ to step away from his podcast.... Read more »IETF v6ops Working Group with Nick Buraglio
The first IPv6 specs were published in 1995, and yet 30 years later, we still have a pretty active IETF working group focused on “developing guidelines for the deployment and operation of new and existing IPv6 networks.” (taken from the old charter; they updated it in late October 2025). Why is it taking so long, and what problems are they trying to solve?
Nick Buraglio, one of the working group chairs, provided some answers in Episode 203 of the Software Gone Wild podcast.
TCG065: AutoCon 4 Recap, AI Tools, MCP’s First Birthday, and More
In this year-end episode, William and Eyvonne recap their experiences at AutoCon 4 in Austin, Texas. They discuss the conference’s new multi-track format, including Eyvonne’s presentation in the leadership track on why technical projects fail. The conversation dives into how AI tools like Google Gemini can augment – not replace – human creativity, from research... Read more »UET Protocol: How the NIC constructs packet from the Work Entries (WRE+SES+PDS)
Semantic Sublayer (SES) Operation
[Rewritte 12. Dec-2025]
After a Work Request Entity (WRE) is created, the UET provider generates the parameters needed by the Semantic Sublayer (SES) headers. At this stage, the SES does not construct the actual wire header. Instead, it provides the header parameters, which are later used by the Packet Delivery Context (PDC) state machine to construct the final SES wire header, as explained in the upcoming PDC section. These parameters ensure that all necessary information about the message, including addressing and size, is available for later stages of processing.
Fragmentation Due to Guaranteed Buffer Limits
In our example, the data to be written to the remote GPU is 16 384 bytes. The dual-port NIC in figure 5-5 has a total memory capacity of 16 384 bytes, divided into three regions: a 4 096-byte guaranteed per-port buffer for Eth0 and Eth1, and an 8 192-byte shared memory pool available to both ports. Because gradient synchronization requires lossless delivery, all data must fit within the guaranteed buffer region. The shared memory pool cannot be used, as its buffer space is not guaranteed.
Since the message exceeds the size of the guaranteed buffer, it must be fragmented. The UET provider splits the 16 384-byte Continue reading
NAN108: Perspectives, Hopes, and Challenges of Young Network Engineers
Let’s hear from the next generation of network engineers. Eric Chou sits down with Sem Eyob and Damon Hoody, two early-career network engineers, to talk about how they got into the profession and where they hope to go. They share their views on AI and its effect on their generation, their struggles finding entry level... Read more »D2DO289: Instana: Leading the Future of Observability (Sponsored)
As AI tools and agentic AI become part of how applications are developed, delivered, and managed, application performance monitoring and observability have to adapt. Ned Bellavance sits down with Drew Flowers and Jacob Yackenovich from IBM Instana about where these fields sit today, and the potential impacts of AI. They detail the challenges of application... Read more »Simplifying SR-TE with mesh templates
A big problem with deploying traffic engineering is configuration complexity. This has now been solved.
Why use Traffic Engineering
Typical reasons for using traffic engineering are:
- Send some traffic via a low latency path
- Send A/B streams via different paths
Evergreen: The Big Ball of Mud
In 2007, Jeff Atwood published a legendary blog post summarizing a 1997 paper by Brian Foote and Joseph Yoder.
Reading that blog post (or the original paper), the inevitable conclusion is that we haven’t made much progress in the last 20 years. Even worse, almost every single pathological architecture described in that blog post applies quite well to real-life organically grown networks.
2026 INFINITI QX80 Autograph 4WD: SUV Mewah dengan Lompatan Teknologi Baru
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Desain Eksterior yang Semakin Berwibawa
Generasi terbaru 2026 INFINITI QX80 Autograph 4WD hadir dengan tampilan yang lebih tegas dan modern. Desain bodinya terlihat tebal namun tetap elegan. Bentuk gril dark chrome kini memberi kesan premium sejak pandangan pertama. Selain itu, velg 22 inci dengan finishing two-tone membuat tampilannya semakin berkelas. Karena itu, QX80 Autograph 4WD tidak hanya sekadar SUV besar, tetapi juga simbol status yang nyata.
Selain tampilan solid, fitur eksteriornya juga mendukung kemudahan. Pengemudi mendapatkan akses pintu otomatis, INFINITI Light Path, serta puddle lights yang membantu saat malam. Lalu, roof dual-pane moonroof memberi atmosfer kabin yang lebih lapang dan mewah. Semua elemen tersebut bersatu menciptakan identitas baru yang lebih kuat.
Interior Ultra Mewah dengan Kemudahan Maksimal
Masuk ke dalam kabin, QX80 Autograph 4WD langsung menunjukkan standar kenyamanan kelas atas. Material semi-aniline leather dengan pola dot quilting terasa sangat lembut. Kursi baris pertama dan kedua punya fitur heated, ventilated, dan massage, sehingga perjalanan jauh terasa nyaman. Bahkan baris ketiga sudah Continue reading
PP090: Why Native Controls Aren’t Enough to Protect Your Cloud Workspaces (Sponsored)
Cloud-based workspaces such as Google Workspace are often the backbone of an organization. But they also face threats from spam and phishing, account takeovers, and illicit access to sensitive documents and files. On today’s Packet Protector we talk with sponsor Material Security about how it brings additional layers of protection to Google Workspace, including email... Read more »HS120: Eight New Year’s Resolutions for 2026
As you wind down 2025, what should you be planning to do for 2026? The Heavy Strategy team breaks it down for you with eight resolutions for the new year. From setting an AI strategy to cloud optimization, Johna and John can help you enter the new year prepared for what’s next. Other resolutions include... Read more »