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Category Archives for "Networking"

Migrating a Data Center Fabric to VXLAN

Darko Petrovic made an excellent remark on one of my LinkedIn posts:

The majority of the networks running now in the Enterprise are on traditional VLANs, and the migration paths are limited. Really limited. How will a business transition from traditional to whatever is next?

The only sane choice I found so far in the data center environment (and I know it has been embraced by many organizations facing that conundrum) is to build a parallel fabric (preferably when the organization is doing a server refresh) and connect the new fabric with the old one with a layer-3 link (in the ideal world) or an MLAG link bundle.

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Palo Alto Object and Policy Cleanup with pan-os-php

Palo Alto Object and Policy Cleanup with pan-os-php

Hi all, welcome back to yet another Palo Alto Automation post. If you work with firewalls, you know that one of the most time-consuming tasks is decommissioning a single resource or an entire subnet from the firewall (aka removing all the references related to the resource). Let's imagine you have thousands of address objects and several hundred security policies. Now, suppose we decommissioned a server and our task is to remove any references we may have in the firewall. It could be an address object, a member in an address group, or a reference in a security policy. Removing this manually would take a lot of time, so in this blog post, let's look at a very simple way of cleaning this up using pan-os-php.

The Problem with the Manual Approach

Here is the problem with the manual approach. Let’s say we are trying to decommission the IP address 10.10.10.25. Let's say we have an address object created for this server, and it has been referenced in a few address groups and several security policies. If you try to remove the address object first, the firewall will complain because the object is being referenced elsewhere. So, you Continue reading

Linux: Mount Remote Directories With SSHFS

The Secure Shell (SSH) isn’t just about allowing you to remote into servers to tackle admin tasks. Thanks to this secure networking protocol, you can also mount remote directories with the help of the SSH File System (SSHF). SSHFS uses SFTP (SSH File Transfer Protocol) to mount remote directories to a local machine using secure encryption, which means the connection is far more secure than your standard FTP. As well, once a remote directory is mounted, it can be used as if it was on the local machine. Consider SSHFS to be a more secure way of creating network shares, the only difference is you have to have SSHFS installed on any machine that needs to connect to the share (whereas with Samba, you only have to have it installed on the machine hosting the share). Let’s walk through the process of getting SSHFS up and running, so you can securely mount remote directories to your local machine. What You’ll Need To make this work, you’ll need at least two Linux machines. These machines can be Ubuntu or Fedora-based, because SSHFS is found in the standard repositories for most Linux distributions. You’ll also need a user with Continue reading

Review: Gowin 1U 2x25G (Alder Lake – N305)

Introduction

Gowin logo

Last month, I took a good look at the Gowin R86S based on Jasper Lake (N6005) CPU [ref], which is a really neat little 10G (and, if you fiddle with it a little bit, 25G!) router that runs off of USB-C power and can be rack mounted if you print a bracket. Check out my findings in this [article].

David from Gowin reached out and asked me if I was willing to also take a look their Alder Lake (N305) CPU, which comes in a 19” rack mountable chassis, running off of 110V/220V AC mains power, but also with 2x25G ConnectX-4 network card. Why not! For critical readers: David sent me this machine, but made no attempt to influence this article.

Hardware Specs

Gowin overview

There are a few differences between this 19” model and the compact mini-pc R86S. The most obvious difference is the form factor. The R86S is super compact, not inherently rack mountable, although I 3D printed a bracket for it. Looking inside, the motherboard is mostly obscured bya large cooling block with fins that are flush with the top plate. There are 5 copper ports in the front: 2x Intel i226-V (these Continue reading

Global Protect Authentication Cookies and Prevent Multiple MFA Prompts

Global Protect Authentication Cookies and Prevent Multiple MFA Prompts

In this blog post, let's look at a common scenario where users face two MFA prompts when trying to connect to Global Protect VPN. Typically, this happens because MFA has been set up for both the portal and the gateway.

When a user connects to GP, the user first logs into the portal and completes the MFA, then, they automatically attempt to connect to the gateway, which triggers another prompt. We'll look at how to prevent two MFA prompts using authentication cookies, so the user only needs to complete the MFA once.

Cookie authentication simplifies the authentication process for users because they will no longer be required to log in to both the portal and the gateway in succession or complete multiple MFAs to authenticate to each. This improves the user experience by minimizing the number of times the users enter credentials.

To keep things simple, when a user logs into Global Protect, we can configure it to generate a 'cookie.' This cookie allows the user to re-authenticate automatically without having to re-enter their credentials or go through MFA again. It's similar to how web browsers remember your login details for websites; once Continue reading

Hacking Terraform

Hacking Terraform

In a previous blog post, I talked about how Terraform's native capabilities don't fully cover comprehensive IP address management, which can make network configurations a bit tricky.

In this post, I’m going to dive into a practical approach for handling IP addresses in Terraform. I'll show you how to leverage an external data source and use a Python script to process IP address operations, then integrate the results back into Terraform.

Introduction to External Data Source

In Terraform, a data source allows you to retrieve information from external systems or services, which you can then use in your configurations. Unlike resources, which are used to manage the lifecycle of infrastructure components, data sources are read-only. They provide a way to fetch data that you might need when setting up or configuring your infrastructure. This is especially useful when you want to incorporate existing information without directly managing the components within your Terraform scripts.

A simple data source in Terraform looks like this:

data "external" "ip" {
  id = "ip"
}

Sample External Data Source

A lot of providers provide external data sources to interact with their systems and get configuration state. A data source in Terraform can range from a Continue reading

The Hedge 237: What’s Wrong with Vendors?

Looking at changes in the market in the last ten years, it certainly seems like vendors work less toward innovation and more towards locking customers in to revenue streams. Chris Emerick, Dave Taht, and Russ White decided it’s time to talk about. What’s wrong with vendors? And since everything can’t be wrong with vendors, where are they doing the right thing?
 

 
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A recent spate of Internet disruptions

Cloudflare Radar is constantly monitoring the Internet for widespread disruptions. In mid-July, we published our Q2 2024 Internet Disruption Summary, and here we examine several recent noteworthy disruptions detected in the first month of Q3, including traffic anomalies observed in Bangladesh, Syria, Pakistan, and Venezuela.

Bangladesh

Violent student protests in Bangladesh against quotas in government jobs and rising unemployment rates led the government to order the nationwide shutdown of mobile Internet connectivity on July 18, reportedly to “ensure the security of citizens.” This government-directed shutdown ultimately became a near-complete Internet outage for the country, as broadband networks were taken offline as well. At a country level, Internet traffic in Bangladesh dropped to near zero just before 21:00 local time (15:00 UTC). Announced IP address space from the country dropped to near zero at that time as well, meaning that nearly every network in the country was disconnected from the Internet.

However, ahead of this nationwide shutdown, we observed outages across several Bangladeshi network providers, perhaps foreshadowing what was to come. At AS24389 (Grameenphone), a complete Internet outage started at 01:30 local time on July 18 (19:30 UTC on July 17), with a total loss of both Internet Continue reading

A recent spate of Internet disruptions

Cloudflare Radar is constantly monitoring the Internet for widespread disruptions. In mid-July, we published our Q2 2024 Internet Disruption Summary, and here we examine recent several noteworthy disruptions detected in the first month of Q3, including traffic anomalies observed in Bangladesh, Syria, Pakistan, and Venezuela.

Bangladesh

Violent student protests in Bangladesh against quotas in government jobs and rising unemployment rates led the government to order the nationwide shutdown of mobile Internet connectivity on July 18, reportedly to “ensure the security of citizens.” This government-directed shutdown ultimately became a near-complete Internet outage for the country, as broadband networks were taken offline as well. At a country level, Internet traffic in Bangladesh dropped to near zero just before 21:00 local time (15:00 UTC). Announced IP address space from the country dropped to near zero at that time as well, meaning that nearly every network in the country was disconnected from the Internet.

However, ahead of this nationwide shutdown, we observed outages across several Bangladeshi network providers, perhaps foreshadowing what was to come. At AS24389 (Grameenphone), a complete Internet outage started at 01:30 local time on July 18 (19:30 UTC on July 17), with a total loss of both Internet Continue reading

Bytes from IETF 120 – Deep Space IP

It has been an enduring fascination to see how we could use packet networking in the context of digital communications in space. Why can't we just use the IP protocol suite and declare success? The tricky issue with space is that it is really very big!

Interesting: Crafting Endless AS Paths in BGP

Vincent Bernat documented a quirk I hope you’ll never see outside of a CCIE lab: combining BGP confederations with AS-override can generate endless AS paths.

I agree entirely with his conclusions (avoid both features). However, I still think that replacing an AS within the confederation part of an AS path (which should belong to a single well-managed AS) is not exactly the most brilliant idea I’ve seen.

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