Multicast IGMP – Internet Group Management Protocol (II)
In the previous post, we covered the basics of multicast. In this post, we will focus on IGMP, Internet Group Management Protocol.
Just as a quick recap, in multicast, the source application (sender) sends multicast traffic to a multicast group address. Somewhere in the network, a receiver wants that traffic stream, so the receiver needs a way to signal that interest.
The router closest to the source is called the First Hop Router (FHR), and the router closest to the receiver is called the Last Hop Router (LHR). Between these two points, the multicast network, meaning all multicast-enabled routers, needs to build a loop-free tree that connects the sender to all interested receivers. IGMP plays a key role in making that happen.
Multicast Introduction (I)
With multicast, the source sends only a single copy of the traffic into the network. As that traffic moves through the network, it is replicated
Suresh Vinasiththamby
IGMP Introduction
IGMP is the protocol used by receivers to signal their interest in multicast traffic. When a host wants to receive a multicast stream, it sends an IGMP Membership Report, also known as an IGMP join, to the multicast group address.
Multicast Introduction (I)
Multicast is one of those topics I have been meaning to learn properly for a long time. When I did my JNCIS-ENT about eight years ago, I studied multicast, but I honestly do not remember much of it now.
I recently started doing some revision and decided to write a series of blog posts as I go through it again. I want something I can come back to in the future without having to relearn everything from scratch. Hopefully, as a reader, you will also find it useful and easy to follow. If you want to learn multicast, I am going to assume you are already familiar with unicast and broadcast.
As always, if you find this post helpful, press the ‘clap’ button. It means a lot to me and helps me know you enjoy this type of content. If I get enough claps for this series, I’ll make sure to write more on this specific topic.
Unicast
Unicast is the most common method of IP communication. It is simply a one-to-one conversation between two devices. One device sends traffic, and one specific device receives it. Most of what we do on a network every day is unicast. Continue reading
HN811: What AI Startups Get Wrong
What is the real-world impact of AI on network operations? Drew and Ethan have a chat with Carlos Pignataro, Founder & Principal at Blue Fern Consulting, to cut through the AI hype machine. Carlos offers a thoughtful, balanced take on where the industry is headed, and where it’s missing the mark. Together they discuss Intent-Based... Read more »Hedge 293: Moore’s Law
Is there an interaction between Moore’s Law and network computing? If so, what is the relationship? How do advances in silicon capabilities and network speeds and feeds rely and drive one another. Geoff Huston joins Russ on this episode of the Hedge to look at a bit of the history.
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Route leak incident on January 22, 2026
On January 22, 2026, an automated routing policy configuration error caused us to leak some Border Gateway Protocol (BGP) prefixes unintentionally from a router at our data center in Miami, Florida. While the route leak caused some impact to Cloudflare customers, multiple external parties were also affected because their traffic was accidentally funnelled through our Miami data center location.
The route leak lasted 25 minutes, causing congestion on some of our backbone infrastructure in Miami, elevated loss for some Cloudflare customer traffic, and higher latency for traffic across these links. Additionally, some traffic was discarded by firewall filters on our routers that are designed to only accept traffic for Cloudflare services and our customers.
While we’ve written about route leaks before, we rarely find ourselves causing them. This route leak was the result of an accidental misconfiguration on a router in Cloudflare’s network, and only affected IPv6 traffic. We sincerely apologize to the users, customers, and networks we impacted yesterday as a result of this BGP route leak.
We have written multiple times about BGP route leaks, and we even record route leak events on Cloudflare Radar for anyone to view and learn from. To get Continue reading
MUST WATCH: BGP: the First 18 Years
If you’re at all interested in the history of networking, you simply MUST watch the BGP at 18: Lessons In Protocol Design lecture by Dr. Yakov Rekhter recorded in 2007 (as you can probably guess from the awful video quality) (HT: Berislav Todorovic via LinkedIn).
IPB192: IPv6 Lab Update
Thinking of setting up an IPv6 lab this year? Our hosts dive into a major update on building and testing modern IPv6 networks, focusing on the game-changing “IPv6-mostly” architecture. They break down the essential components you need to get this working, including DHCP Option 108 and the nitty gritty of client support. In this episode,... Read more »Ingress Security for AI Workloads in Kubernetes: Protecting AI Endpoints with WAF
AI Workloads Have a New Front Door
For years, AI and machine learning workloads lived in the lab. They ran as internal experiments, batch jobs in isolated clusters, or offline data pipelines. Security focused on internal access controls and protecting the data perimeter.
That model no longer holds.
Today, AI models are increasingly part of production traffic, which is driving new challenges around securing AI workloads in Kubernetes. Whether serving a large language model for a customer-facing chatbot or a computer vision model for real-time analysis, these models are exposed through APIs, typically REST or gRPC, running as microservices in Kubernetes.
From a platform engineering perspective, these AI inference endpoints are now Tier 1 services. They sit alongside login APIs and payment gateways in terms of criticality, but they introduce a different and more expensive risk profile than traditional web applications. For AI inference endpoints, ingress security increasingly means Layer 7 inspection and WAF (Web Application Firewall) level controls at the cluster edge. By analyzing the full request payload, a WAF can detect and block abusive or malicious traffic before it ever reaches expensive GPU resources or sensitive data. This sets the stage for protecting AI workloads from both operational Continue reading
N4N047: Virtual Router Redundancy Protocol (VRRP)
Go beyond the basics to understand the mechanics that keep your default gateway from becoming a single point of failure. Ethan and Holly demystify Virtual Router Redundancy Protocol (VRRP), which helps provide network redundancy. They break down everything from the VRRP election protocol to the protocol’s unique communication methods. They also look back at previous... Read more »Why Doesn’t netlab Use X for Device Configuration Templates?
Petr Ankudinov made an interesting remark when I complained about how much time I wasted waiting for Cisco 8000v to boot when developing netlab device configuration templates:
For Arista part - just use AVD with all templates included and ANTA for testing. I was always wondering why netlab is not doing that.
Like any other decent network automation platform, netlab uses a high-level data model (lab topology) to describe the network. That data model is then transformed into a device-level data model, and the device-level data structures are used to generate device configurations.
D2DO292: AI, Augmented Engineers, and the Timeless Principles of Software Architecture
Ned and Kyler sit down with industry analyst Jon Collins for a fun and free-ranging discussion that covers everything from the changing landscape of software engineering to the importance of good architecture (physical and digital). They tackle the pros and cons of “Vibe Coding” as well as the “Augmentation Gap”, the idea that AI tools... Read more »NAN111: Automation, AI, and the Future of Branch Networking: Inside Cisco Unified Branch (Sponsored)
In this sponsored episode, Eric sits down with Lee Peterson, VP of Product Management for Secure WAN, at Cisco. Together they discuss how Cisco Unified Branch is helping organizations scale, automate, and secure their distributed environments. They also define the Branch Network, discuss the major challenges facing network teams, and walk through Cisco’s vision of... Read more »Lab: Distributing Level-2 IS-IS Routes into Level-1 Areas
One of the major differences between OSPF and IS-IS is their handling of inter-area routes. Non-backbone OSPF intra-area routes are copied into the backbone area and later (after the backbone SPF run) copied into other areas. IS-IS does not copy level-2 routes into level-1 areas; level-1 areas (by default) behave like totally stubby OSPF areas with the level-1 routers using the Attached (ATT) bit of level-1-2 routers in the same area to generate the default route.
HW068: Vibe Coding for Wireless Engineers
Is AI just a fad or is it fundamentally changing Wi-Fi operations? Keith sits down with Robert Boardman to discuss the reality of AI-augmented Wi-Fi engineering. Robert describes AI as a tool, and explains how it can be useful for automating monotonous tasks and proactive troubleshooting. They also explore the human factor and how experience... Read more »PP093: Security Priorities for 2026 – A Roundtable Discussion
The start of a new year is a good time to assess what’s important. We’ve gathered some Packet Protector listeners to talk about their security priorities for 2026 in a roundtable discussion with hosts JJ and Drew. We talk about key risks for 2026, whether those risks have changed since last year, use cases for... Read more »NGINX is Retiring: Your Step-by-Step Guide to Replacing Ingress NGINX
Your Curated Webinar & Blog Collection
The Ingress NGINX Controller is approaching retirement, and teams need a clear path forward to manage Kubernetes ingress traffic securely and reliably. To make this transition easier, we’ve created a single, curated hub with all the relevant blogs and webinars. This hub serves as your one-stop resource for understanding the migration to Kubernetes Gateway API with Calico Ingress Gateway.
This curated hub is designed to guide your team from understanding Ingress NGINX retirement, through evaluating options, learning the benefits of Calico Ingress Gateway, and ultimately seeing it in action with webinars and a demo.
Use This Collection to Help You Migrate Safely
One-stop resource: No need to hunt across the site for guidance.- Recommended reading order: Helps teams build knowledge progressively.
- Actionable takeaways: Blogs explain why and how to migrate; webinars show it in practice.
- Demo access: Direct link to schedule personalized support for your environment.
One-stop resource: No need to hunt across the site for guidance.Recommended Reading
Step 1: Understand the Retirement of Ingress NGINX and the changing landscape
- Read “Ingress NGINX Controller Is Dead: Should You Move to Gateway API?” to understand why NGINX is being retired and what it means for your clusters.
Step 2: Compare Approaches, including Ingress vs. Continue reading
Paito SGP Terbaik dan Terpercaya sebagai Referensi Data SGP yang Konsisten
Daftar Pustaka
Pengantar Pentingnya Paito SGP Terbaik dan Terpercaya
Paito SGP terbaik dan terpercaya menjadi rujukan utama bagi pembaca yang membutuhkan ringkasan data harian secara rapi. Banyak orang memilih paito karena tampilannya sederhana namun informatif. Selain itu, paito memudahkan pencatatan tanpa harus membuka data satu per satu.
Di tengah banyaknya sumber, kualitas paito menentukan kepercayaan. Oleh sebab itu, memilih paito SGP yang tepat membantu pembaca memperoleh data SGP yang akurat dan konsisten. Dengan pendekatan ini, pembaca dapat memantau result SGP secara terstruktur.
Apa Itu Paito SGP dan Fungsi Utamanya
Secara umum, paito SGP merupakan tabel visual yang menyusun hasil SGP berdasarkan hari dan tanggal. Fungsi utamanya adalah menyederhanakan Continue reading
Keindahan dan Legenda di Dalam Gua Jatijajar Kebumen
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Sejarah Menarik Gua Jatijajar
Gua Jatijajar berada di Kebumen, Jawa Tengah. Lokasinya berada di wilayah perbukitan kapur yang sangat memukau. Selain itu, gua ini menawarkan kombinasi wisata alam dan kisah sejarah yang membuat banyak wisatawan tertarik.
Konon, masyarakat menemukan gua ini pada abad ke-19. Mereka menemukan gua saat sedang menggali tanah di area persawahan. Sejak itu, warga setempat mulai mengenali potensi wisata gua tersebut. Walau begitu, pemerintah kemudian mengembangkan kawasan ini lebih modern.
Nama Jatijajar memiliki arti unik. Kata “jati” berarti pohon jati dan “jajar” berarti berjajar rapi. Tempat ini dahulu dikelilingi pohon jati yang berdiri berderet. Oleh karena itu, nama tersebut melekat hingga sekarang.
Menariknya, gua ini juga menyimpan kisah legenda Raden Kamandaka atau Lutung Kasarung. Kisah ini menambah daya tarik budaya dan spiritual. Wisatawan dapat melihat beberapa diorama yang menggambarkan perjalanan tokoh tersebut. Dengan demikian, mereka bisa memahami cerita lokal sambil menikmati suasana alam khas pegunungan kapur.
Selain itu, pemerintah daerah terus menjaga kelestarian gua. Mereka melakukan berbagai perawatan. Jadi, area wisata tetap aman dan nyaman. Hingga kini, Gua Jatijajar menjadi salah satu ikon wisata unggulan Kebumen. Bahkan, banyak wisatawan Continue reading
KERIS TAMING SARI: SENJATA LEGENDA YANG SARAT NILAI SEJARAH
Daftar Pustaka
Asal Usul Keris Taming Sari
Legenda Keris Taming Sari selalu menarik perhatian banyak orang. Senjata ini terkenal sebagai keris sakti yang menyimpan kisah luar biasa. Menurut cerita rakyat, keris ini pertama kali muncul di Kerajaan Majapahit. Keris tersebut kemudian menjadi milik Hang Tuah, seorang pahlawan terkenal dari Kesultanan Malaka.
Para pandai besi hebat dipercaya menempa keris ini dengan teknik tingkat tinggi. Karena itu, Taming Sari dianggap unik. Selain itu, setiap detailnya menunjukkan karya seni kelas tinggi. Walaupun banyak legenda, para sejarawan tetap menilai benda ini sebagai simbol kejayaan masa lalu.
Selain sejarah Majapahit, hubungan dengan Malaka juga sangat kuat. Hang Tuah memakai keris ini dalam berbagai pertempuran. Oleh karena itu, sosok Hang Tuah selalu identik dengan Keris Taming Sari. Cerita tersebut terus bertahan dari generasi ke generasi.
Lebih jauh lagi, masyarakat percaya bahwa keris ini memiliki kekuatan mistis. Banyak dongeng menyebutkan keris mampu menang sendiri tanpa tuannya. Hal tersebut membuat banyak orang menganggapnya sebagai benda pusaka paling berpengaruh di Nusantara.
Ciri Khas Keris Taming Sari
Bila membahas keris legendaris ini, Continue reading
Burung yang Hanya Ada di Indonesia: Cucakrawa
Daftar Pustaka
Keindahan Burung Endemik dengan Suara Merdu
Burung Cucakrawa atau dikenal sebagai Cucak Rawa menjadi salah satu burung yang sangat istimewa di Indonesia. Selain itu, burung ini juga memiliki kicauan merdu yang memukau banyak pecinta burung. Karena itu, banyak orang merasa terpikat oleh pesonanya. Bahkan, mereka rela menghabiskan banyak uang untuk memilikinya. Namun, keberhasilan dalam melestarikan burung endemik ini tetap menjadi fokus penting.
Selain itu, Cucakrawa juga memperlihatkan warna tubuh yang menarik. Bulunya terlihat cokelat zaitun dengan kombinasi putih bersih di beberapa bagian. Kemudian, bentuk tubuhnya tampak gagah dan elegan. Karena itu, burung ini semakin populer. Hingga kini, keberadaannya tetap menjadi simbol kekayaan alam Indonesia.
Asal Usul dan Habitat Alami
Secara ilmiah, Cucakrawa memiliki nama Pycnonotus zeylanicus. Burung ini hanya hidup di Indonesia, terutama di wilayah Sumatra, Jawa, dan sebagian Kalimantan. Mereka hidup di rawa, hutan sekunder, serta daerah lembap. Oleh karena itu, mereka sangat bergantung pada lingkungan yang alami dan terjaga.
Selain itu, burung ini juga senang tinggal pada pepohonan tinggi. Mereka memilih tempat yang Continue reading