Expanding a Running Netlab Topology

One of the happy netlab users sent me an interesting challenge:

  • He’s built a large lab and added tons of extra configuration to the lab devices.
  • Afterwards, he realized he’d like to add a few more devices to the lab and was worried about losing all the changes he had made.

Unfortunately, you cannot add new devices to an already-running lab. You must shut down the lab, change the topology description, and start a new lab. However, there are things you can do to preserve the extra work you already did:

Read more …

AWS Transit Gateway Introduction (VI)

AWS Transit Gateway Introduction (VI)

In the previous post, we covered VPC Peering, which is a quick and easy way to create a connection between two VPCs. We also discussed its limitations, primarily that it is non-transitive. This means if VPC 'A' is peered with VPC 'B', and VPC 'B' is peered with VPC 'C', VPC 'A' cannot communicate with VPC 'C' through VPC 'B'. Because of this, to connect multiple VPCs together, you need to create a full mesh, where every VPC has a direct peering connection to every other VPC.

AWS VPC Peering
In this post, we will continue to expand on VPC connectivity by looking at what AWS VPC Peering is and how to configure one.
AWS Transit Gateway Introduction (VI)PacketswitchSuresh Vina
AWS Transit Gateway Introduction (VI)

This complexity (when you have many VPCs) is why, in this post, we will look at AWS Transit Gateway (TGW). A Transit Gateway is an incredibly important networking resource in AWS that solves these scaling challenges. You will see the TGW featured in many modern AWS architecture diagrams because of the flexibility and simplicity it provides.

As always, if you find this post helpful, press the ‘clap’ button. It means a lot to me and helps me know you enjoy Continue reading

AWS VPC Peering (V)

AWS VPC Peering (V)

Welcome back to the AWS Networking series. So far, we have covered a wide range of foundational topics. We started with the basics of building a VPC, creating subnets, configuring route tables, and providing Internet access with an Internet Gateway and a NAT Gateway. We then looked at the difference between stateful Security Groups attached to an instance's ENI and stateless Network ACLs applied at the subnet level. Most recently, we covered how to build a hybrid network using a Site-to-Site VPN.

In this post, we will continue to expand on VPC connectivity by looking at what AWS VPC Peering is and how to configure one.

If you are completely new to AWS networking, I highly recommend checking out our introductory posts linked below. However, if you are already familiar with the basics, you can carry on with this post.

AWS Networking Fundamentals
If you’re brand new to AWS, don’t worry. This post focuses on the basics of AWS networking. General networking knowledge is helpful but not required - I’ll try to explain things clearly so everyone can follow along.
AWS VPC Peering (V)PacketswitchSuresh Vina
AWS VPC Peering (V)
As always, if you find this post helpful, press the ‘clap’ button. Continue reading

Build Your Own Private Cloud at Home With Docker

If you’re like me, you depend on a lot of systems and services, even within your home LAN. Because I work from home, that’s amplified to the point where I need certain applications available to me that aren’t hosted by a third party, for flexibility, ease of use, reliability and security. Thankfully, Docker is there to make deploying those apps and services considerably easier; otherwise, I’d wind up having to first deploy a collection of virtual machines (VMs), keep them running and worry about upgrading/managing them efficiently. Yeah, Docker makes this entire process easier. Even better, I can spin up those apps and services in seconds, instead of having to go the traditional route, which can often take quite a bit longer to deploy. But what are the apps and services that I depend on for my LAN to keep me productive? Surprise, surprise: I have a list, and here it is. Nextcloud

Worth Reading 070325


Ossification is still a major issue in today’s networking environment, and while it’s not a theme in the architecture of the transmission platform, we see it in the Internet Protocol itself, in our transport protocols, in our routing protocols, and in various applications.


The Federal Bureau of Investigation (FBI) is issuing this Public Service Announcement to warn the public about cyber criminals exploiting Internet of Things (IoT)1 devices connected to home networks to conduct criminal activity using the BADBOX 2.0 botnet2.


hile the architecture of the 900 series had no support for partitioning memory (requiring cooperation for multi-user activity), and many ran without any operating system at all, there was an optional NPL interface.


Most protocols do not have the equivalent of an X-Forwarded-For header. To solve this, HAProxy came up with the PROXY protocol, which is a Layer 4 protocol that allows a proxy server to communicate client information to a backend server.


If you built a proper technology strategy in the first place, driven by the business strategy, then no matter what is happening don’t ignore it, and don’t throw it out—update it and stick to it!

AWS Site-to-Site VPN (IV)

AWS Site-to-Site VPN (IV)

So far in the AWS Networking series, we have covered VPCs, subnets, route tables, Internet Gateways, NAT Gateways, EC2 instances, Security Groups, Network ACLs, and Elastic Network Interfaces. In this post, we will look at using a Site-to-Site VPN in AWS so you can securely connect your on-premise workloads to and from your AWS environment. This is a very important aspect of AWS networking, and this is a service you will use almost always.

If you have been following the series, you can easily follow along with this post. If you just stumbled upon this post, you can still continue, assuming you are already familiar with AWS networking basics. However, if you are completely new to AWS, I highly recommend checking out the previous posts linked below.

AWS Networking Fundamentals
If you’re brand new to AWS, don’t worry. This post focuses on the basics of AWS networking. General networking knowledge is helpful but not required - I’ll try to explain things clearly so everyone can follow along.
AWS Site-to-Site VPN (IV)PacketswitchSuresh Vina
AWS Site-to-Site VPN (IV)

Why Do We Need a VPN to AWS?

When we launch an instance in a public subnet with a public IP address, we have seen that we can connect to Continue reading

Minding the Gap: SDS That Carries You Through Last Mile

Data center modernization is inevitable to keep pace with today’s performance-intensive workloads, which are growing especially rapidly in the financial services and e-commerce sectors. Software-defined storage (SDS) offers the promise of greater agility, scalability and reduced costs, making it a compelling part of the platform architect’s vision of a streamlined, software-driven infrastructure. A common priority for modernization is retiring traditional Fibre Channel (FC) SANs, which are perceived as legacy and complex. While still adequate for many application workloads, performance gaps exist in SDS block storage solutions that are engineered into legacy FC SANs, which cannot support the organization’s mission-critical application workloads. Once reserved as the primary storage tier for traditional workloads,

Palo Alto Upgrade from 10.2 to 11.2 (PA-440)

Palo Alto Upgrade from 10.2 to 11.2 (PA-440)

I have PA-440 in my home lab and was happily running PAN-OS 10.2.10-h9. But with the recent announcement that PAN-OS 10.2 will enter limited support from 26th August 2025, I decided it was time to upgrade. I was deciding between 11.1 and 11.2 for a while, but after reading through a few forums and discussions, I ended up choosing 11.2, specifically PAN-OS 11.2.4-h7.

Since I was already on 10.2, I could upgrade directly to 11.2 without going through any intermediate versions. As per the upgrade guide, all I had to do was download the 11.2.0 base image, then download and install 11.2.4-h7.

Palo Alto Upgrade from 10.2 to 11.2 (PA-440)
💡
Just to clarify, you only need to download the 11.2.0 base image, there’s no need to install it.
Palo Alto Upgrade from 10.2 to 11.2 (PA-440)

After downloading both the base image and the target image, just click 'Install' on the target image. As usual, make sure to take a backup before starting. If you’re running in HA, you can upgrade the firewalls one at a time without any downtime.

Palo Alto Upgrade from 10.2 to 11.2 (PA-440)
Palo Alto Upgrade from 10.2 to 11.2 (PA-440)

The whole process took about 10 to 15 minutes, and now I'm running 11.2.4-h7. If I come across any issues, I'll be sure to update this post.

Palo Alto Upgrade from 10.2 to 11.2 (PA-440)

Worth Reading: Expert Generalists

Martin Fowler published an interesting article about Expert Generalists. Straight from the abstract:

As computer systems get more sophisticated we’ve seen a growing trend to value deep specialists. But we’ve found that our most effective colleagues have a skill in spanning many specialties.

Also:

There are two sides to real expertise. The first is the familiar depth: a detailed command of one domain’s inner workings. The second, crucial in our fast-moving field is the ability to learn quickly, spot the fundamentals that run beneath shifting tools and trends, and apply them wherever we land.

Remember how I told you to focus on the fundamentals? 😎

Keep reading

A Detailed Look at Calico Cloud Free Tier

Why Calico Cloud Free Tier?

As Kubernetes environments grow in scale and complexity, platform teams face increasing pressure to secure workloads without slowing down application delivery. But managing and enforcing network policies in Kubernetes is notoriously difficult—especially when visibility into pod-to-pod communication is limited or nonexistent. Teams are often forced to rely on manual traffic inspection, standalone logs, or trial-and-error policy changes, increasing the risk of misconfiguration and service disruption. Safe policy management and microsegmentation becomes a daunting task without clear knowledge or insight into which services should communicate with each other.

In this detailed look, we’ll explore how Calico Cloud Free Tier builds upon Calico Open Source, and helps platform teams visualize traffic with a dynamic service graph, simplifies policy management, and even analyzes actual traffic to recommend policies.

What is Calico Cloud Free Tier?

Calico Cloud Free Tier is a managed SaaS, no-cost offering that extends the capabilities of Calico Open Source 3.30 and higher to help Kubernetes teams improve network visibility, simplify policy management, and improve security by simplifying microsegmentation. Designed for single-cluster environments, it provides platform engineers and operators with powerful observability and policy management tools. With a seamless onboarding experience for users already Continue reading

Site-to-site VPN between AWS and Palo Alto (Static & BGP)

Site-to-site VPN between AWS and Palo Alto (Static & BGP)

In this blog post, we'll look at how to create a site-to-site VPN between AWS and a Palo Alto firewall. We'll go through both static routing and BGP options. This post assumes you're already somewhat familiar with AWS and Palo Alto, so we won't cover the basics like creating a VPC in AWS or setting up zones and policies on the firewall.

AWS Networking Fundamentals
If you’re brand new to AWS, don’t worry. This post focuses on the basics of AWS networking. General networking knowledge is helpful but not required - I’ll try to explain things clearly so everyone can follow along.
Site-to-site VPN between AWS and Palo Alto (Static & BGP)PacketswitchSuresh Vina
Site-to-site VPN between AWS and Palo Alto (Static & BGP)

Overview

To create a VPN connection, you first need a compatible IPsec VPN device, like a firewall or router, at your on-premise location. In AWS, the resource you create to represent this device is called a Customer Gateway. In our example, the customer gateway is the Palo Alto firewall.

To send traffic from your VPC to your on-premise network, you route it to a Virtual Private Gateway (VGW). The VGW is a logical, redundant resource on the AWS side of the connection that you attach to your VPC. It serves as the target in your Continue reading

NAN095: Certification Deep Dive – The New Cisco Automation Track

Cisco recently announced a major evolution to its certification roadmap: starting February 2026, the popular DevNet certifications will transition to a brand-new Automation track. Joining us today is Francois Caen, Product Manager at Cisco, also an expert in network automation and a recognized voice in the Cisco Learning and Certification Community. We talk with Francois... Read more »

Molly-Guard: a Lifesaver on a Ubuntu Server

Have you ever managed to type reload in the wrong terminal window and brought down a core switch (I probably did)? I managed to do the Ubuntu equivalent of that stupidity: I told my main Ubuntu server to sudo poweroff instead of doing that to a Vagrant VM.

Fortunately, the open-source world doesn’t have to rely on the roadmaps created by networking vendors’ product managers; if there’s a big enough pain, someone will solve it.

Read more …

Next Generation SD-WAN in the AI Era

Next Generation SD-WAN in the AI Era

The advent of cloud native applications in the 2025 era (CRM, SaaS, storage, or ERP apps) and the public cloud has caused a re-architecture of traditional WANs based on popular Ethernet and IP across cloud boundaries. Arista has been the thought leader and pioneer of this leaf-spine cloud network for data centers, and now we can see a seamless extension of this concept to the WAN and inter data center using the same principles that have served our customers. The distribution of applications across AI, cloud, SaaS, edge, and enterprise environments creates new challenges for wide area networking architecture and Internet routing to refine branch and WAN networks.

1 … 72 73 74 75 76 … 3,871