Archive

Category Archives for "Networking"

5 Essential Steps to Strengthen Kubernetes Egress Security

Securing what comes into your Kubernetes cluster often gets top billing. But what leaves your cluster, outbound or egress traffic, can be just as risky. A single compromised pod can exfiltrate data, connect to malicious servers, or propagate threats across your network. Without proper egress controls, workloads can reach untrusted destinations, creating serious security and compliance risks. This guide breaks down five practical steps to strengthen Kubernetes egress security, helping teams protect data, enforce policies, and maintain visibility across clusters.

Why Egress Controls Matter 🔐

By default, Kubernetes allows unrestricted outbound communication, meaning any pod can reach any external destination and dramatically increase the attack surface. Implementing egress controls ensures pods can communicate only with explicitly trusted services, containing the impact of a compromised workload and preventing unauthorized data exfiltration or lateral movement.

Granular egress controls are also essential for meeting security and compliance mandates, providing authorization, logging, and monitoring for all external connections.
The image illustrates how a single routable IP can centralize and control all Kubernetes egress traffic to external services through a single firewall rule.
How a single routable IP can centralize and control all Kubernetes egress traffic to external services through a single firewall rule.

Your Kubernetes Egress Security Checklist

To help teams tackle this challenge, we’ve put together a Kubernetes Egress Security Checklist, based on best practices from real-world Continue reading

Some Notes from RIPE-91

The 91st meeting of the RIPE community was held in Bucharest in October this year. It was a busy week and, as usual, there were presentations on a wide variety of topics, including routing, the DNS, network operations, security, measurement and address policies. The following are some notes on presentations that I found to be of interest to me.

OMG: Automatic OSPFv3 Router ID on Cisco IOS

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.

Read more …

Tech Bytes: Why Equinix Should Be Part of Your AI Network Strategy (Sponsored)

AI infrastructure conversations tend to be dominated by GPUs, data center buildouts, and power and water consumption. But networks also play a crucial role, whether to support huge file transfers to a compute cluster, stream telemetry from edge locations to feed AI pipelines, or provide high-speed, low latency connectivity for AI agents. On today’s Tech... Read more »

Adding a Syslog Server to a netlab Lab Topology

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 ;)

Adding a Syslog Server

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.”

Read more …

A Unified ARP Table (and how to get one when you don’t have one)

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.

Network Labs on a Budget

Network Labs on a Budget

"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.

💡
Disclaimer - This post is based on my personal experience and is meant to be general advice only. Everyone’s situation is different, so please do your own research before buying anything. I’m not responsible if you end up purchasing something that doesn’t suit your needs or expectations.

What We Will Cover?

  • Buying a used mini PC
  • Proxmox as the hypervisor (optional)
  • Linux as a VM
  • Containerlab/Netlab, EVE-NG, Cisco CML
  • Proxmox Backup Server (optional)
  • Simplest Option for Absolute Beginners
Network Labs on a Budget
networklab stack

TL;DR

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

Contributing to NTC templates

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.

The strange webserver hot potato — sending file descriptors

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.

My goal

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.

Why?

A few reasons:

  1. Having all bytes bounce on the SNI router triples the number of total file descriptors for the connection. (one on the backend, Continue reading

What’s New in Calico v3.31: eBPF, NFTables, and More

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:

HN802: Unifying Networking and Security with Fortinet SASE: Architecture, Reality, and Lessons Learned (Sponsored)

The architecture and tech stack of a Secure Access Service Edge (SASE) solution will influence how the service performs, the robustness of its security controls, and the complexity of its operations. Sponsor Fortinet joins Heavy Networking to make the case that a unified offering, which integrates SD-WAN and SSE from a single vendor, provides a... Read more »

Worth Reading 102425


I get the sense that hosting a ccTLD today is challenging, not because of the technical stack, but due to Distributed Denial-of-Service (DDoS) concerns


In times of major change–whether in IT or the economy–organizations should take a fresh look at their sourcing strategy. Companies outsourcing key functions need to re-examine the reasoning and scrutinize the results.


Another multivendor development group, the Ultra Accelerator Link (UALink) consortium, recently published its first specification aimed at delivering an open standard interconnect for AI clusters.


The company conducted a nationwide survey of 3,790 people that asked about real-world experiences and expectations around home WiFi performance. I think every ISP I know could have predicted the gist of the responses, but I think ISPs might be surprised at the percentage of people who are unhappy with WiFi.


DNS was not originally designed with security in mind, making it easy for common threats such as DNS spoofing and man-in-the-middle attacks to reroute unsuspecting users to malicious sites, often without detection.

Hedge 285: Post Quantum Crypto

Is 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.

download

DEEP Is Still a Must-Attend Boutique Conference

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.

Read more …

How To Deploy a Local AI via Docker

If you’re tired of worrying about your AI queries or the data you share within them being used to either train large language models (LLMs) or to create a profile of you, there are always local AI options you can use. I’ve actually reached the point where the only AI I use is local. For me, it’s not just about the privacy and security, but also the toll AI takes on the energy grids and the environment. If I can do my part to prevent an all-out collapse, you bet I’m going to do it. Most often, I deploy local AI directly on my machine. There are, however, some instances where I want to quickly deploy a local AI to a remote server (either within my LAN or a server beyond it). When that need arises, I have two choices: Install a local AI service in the same way I install it on my desktop. Containerize it. The benefit of containerizing it is that the locally installed AI is sandboxed from the rest of the system, giving me even more privacy. Also, if I want to stop the locally installed AI, I can do so with a quick and easy Continue reading

Breaking the ‘Shared-Nothing’ Bottleneck: A NoSQL Paradigm

While there is no single storage architecture model that fits all NoSQL databases, the often recommended approach is a distributed, shared-nothing architecture using local storage (often flash-based) at each node. At the storage hardware level, direct-attached storage (DAS) would be an example of shared-nothing architecture. This model provides the desired high performance, low latency, fault tolerance and availability that business-critical NoSQL databases like Cassandra and MongoDB require. While DAS offers significant advantages, it’s counterproductive to today’s data center climate of reduced CapEx, OpEx and sustainability initiatives. At the same time, critical data services inherent in a shared networked storage system, such as storage area networks (SANs), are missing in DAS. However, with today’s SAN solutions, you can have your cake and eat it, too: efficiency, data services, resilience and yes, high performance and low latency, too. Modernizing your data platform to a SAN model, using a supplier with a disaggregated, software-defined architecture, can deliver the performance and fault tolerance your NoSQL database requires without compromising efficiency. Why Shared-Nothing Is Common for NoSQL DAS is a prevalent model for performance-sensitive workloads, like NoSQL databases, because historically local flash, especially

1 … 12 13 14 15 16 … 3,480