RFC1925 Rule 2
According to RFC1925, the second fundamental truth of networking is: No matter how hard you push and no matter what the priority, you can’t increase the speed of light.
However early in the world of network engineering this problem was first observed (see, for instance, Tanenbaum’s “station wagon example” in Computer Networks), human impatience is forever trying to overcome the limitations of the physical world, and push more data down the pipe than mother nature intended (or Shannon’s theory allows).
One attempt at solving this problem is the description of an infinitely fat pipe (helpfully called an “infan(t)”) described in RFC5984. While packets would still need to be clocked onto such a network, incurring serialization delay, the ability to clock an infinite number of packets onto the network at the same moment in time would represent a massive gain in a network’s ability, potentially reaching speeds faster than the speed of light. The authors of RFC5984 describe several attempts to build such a network, including black fiber, on which the lack of light implies data transmission. This is problematic, however, because a lack of information can be interpreted differently depending on the context. A pregnant pause has far different meaning Continue reading
Getting Started With AWS Ansible Module Development and Community Contribution
We often hear from cloud admins and developers that they’re interested in giving back to Ansible and using their knowledge to benefit the community, but they don’t know how to get started. Lots of folks may even already be carrying new Ansible modules or plugins in their local environments, and are looking to get them included upstream for more broad use.
Luckily, it doesn’t take much to get started as an Ansible contributor. If you’re already using the Ansible AWS modules, there are many ways to use your existing knowledge, skills and experience to contribute. If you need some ideas on where to contribute, take a look at the following:
- Creating integration tests: Creating missing tests for modules is a great way to get started, and integration tests are just Ansible tasks!
- Module porting: If you’re familiar with the boto3 Python library, there’s also a backlog of modules that need to be ported from boto2 to boto3.
- Repository issue triage: And of course there’s always open Github issues and pull requests. Testing bugs or patches and providing feedback on your use cases and experiences is very valuable.
The AWS Ansible Content Collections
Starting with Ansible 2.10, the AWS Continue reading
Let’s build a Cloudflare Worker with WebAssembly and Haskell
This is a guest post by Cristhian Motoche of Stack Builders.
At Stack Builders, we believe that Haskell’s system of expressive static types offers many benefits to the software industry and the world-wide community that depends on our services. In order to fully realize these benefits, it is necessary to have proper training and access to an ecosystem that allows for reliable deployment of services. In exploring the tools that help us run our systems based on Haskell, our developer Cristhian Motoche has created a tutorial that shows how to compile Haskell to WebAssembly using Asterius for deployment on Cloudflare.
What is a Cloudflare Worker?
Cloudflare Workers is a serverless platform that allows us to run our code on the edge of the Cloudflare infrastructure. It's built on Google V8, so it’s possible to write functionalities in JavaScript or any other language that targets WebAssembly.
WebAssembly is a portable binary instruction format that can be executed fast in a memory-safe sandboxed environment. For this reason, it’s especially useful for tasks that need to perform resource-demanding and self-contained operations.
Why use Haskell to target WebAssembly?
Haskell is a pure functional languages that can target WebAssembly. As such, It helps developers Continue reading
EVPN Control Plane in Infrastructure Cloud Networking
One of my readers sent me this question (probably after stumbling upon a remark I made in the AWS Networking webinar):
You had mentioned that AWS is probably not using EVPN for their overlay control-plane because it doesn’t work for their scale. Can you elaborate please? I’m going through an EVPN PoC and curious to learn more.
It’s safe to assume AWS uses some sort of overlay virtual networking (like every other sane large-scale cloud provider). We don’t know any details; AWS never felt the need to use conferences as recruitment drives, and what little they told us at re:Invent described the system mostly from the customer perspective.
EVPN Control Plane in Infrastructure Cloud Networking
One of my readers sent me this question (probably after stumbling upon a remark I made in the AWS Networking webinar):
You had mentioned that AWS is probably not using EVPN for their overlay control-plane because it doesn’t work for their scale. Can you elaborate please? I’m going through an EVPN PoC and curious to learn more.
It’s safe to assume AWS uses some sort of overlay virtual networking (like every other sane large-scale cloud provider). We don’t know any details; AWS never felt the need to use conferences as recruitment drives, and what little they told us at re:Invent described the system mostly from the customer perspective.
NFA is officially out of Beta!
It’s been almost a year since our first NFA Beta commit. From there on, we’ve seen the product achieve widespread interest and
The post NFA is officially out of Beta! appeared first on Noction.
NFA is officially out of Beta!
The post NFA is officially out of Beta! appeared first on Noction.
Why Reining in Unnecessary Cloud Spending is IT’s Next Priority in the COVID Era
The faster businesses can understand their cloud consumption habits, clarify policies, and enact accountability, the sooner they can effectively manage their sprawling cloud spend.Thoughts From Networking Field Day 23
I know I’m a little late getting this post out but Networking Field Day 23 was a jam-packed event with lots of things to digest. I wanted to share some quick thoughts about it here that should create some discussion amongst the community, hopefully.
- If you don’t believe that wireless is the new access edge, go look at Juniper. Their campus networking division is basically EX switching and Mist. That’s it. Remember how HPE called Aruba a “reverse acquisition” years ago? And how Aruba essentially took over the networking portion of HPE? Don’t be surprised to see Juniper getting more misty sooner rather than later. And that’s a good thing for everything that isn’t a carrier or service provider router.
- Network monitoring became telemetry and is now transforming into digital experience. What is the difference to me? Monitoring devices tells you point-in-time information. Telemetry gives you the story of those point-in-time measurements over the course of days or weeks and can help you find issues. Experience is all about how that looks to your users. Problems don’t always affect them the same way it might appear on a dashboard. Likewise, things you don’t always see in your alerts can affect Continue reading
Microsoft Exec: How Enterprises are Democratizing Data
During her Interop Digital keynote, Microsoft's Alysa Taylor will discuss how technology has been a catalyst for accelerated value and change in 2020.Why The DPU Is More Important Than The CPU For Nvidia
If you are fairly new to the IT racket, you might be under the impression that the waves of integration and disaggregation in compute, networking, and storage that swept over the datacenter in recent decades were all new, that somehow the issues of complexity and cost did not plague systems of the past. …
Why The DPU Is More Important Than The CPU For Nvidia was written by Timothy Prickett Morgan at The Next Platform.
Tech Bytes: NetMotion Integrates VPNs With The Software Defined Perimeter
Today's Tech Bytes, sponsored by NetMotion Software, explores how NetMotion integrates client VPNs with more modern approaches, including Zero Trust Network Access (ZTNA) and the Software Defined Perimeter. Our guest is Mike Spence, Systems Engineer at NetMotion.Tech Bytes: NetMotion Integrates VPNs With The Software Defined Perimeter
Today's Tech Bytes, sponsored by NetMotion Software, explores how NetMotion integrates client VPNs with more modern approaches, including Zero Trust Network Access (ZTNA) and the Software Defined Perimeter. Our guest is Mike Spence, Systems Engineer at NetMotion.
The post Tech Bytes: NetMotion Integrates VPNs With The Software Defined Perimeter appeared first on Packet Pushers.
Jinja2 Tutorial – Part 5 – Macros
Welcome to the part 5 of Jinja2 Tutorial where we learn all about macros. We'll talk about what macros are, why we would use them and we'll see some examples to help us appreciate this feature better.
Jinja2 Tutorial series
- Jinja2 Tutorial - Part 1 - Introduction and variable substitution
- Jinja2 Tutorial - Part 2 - Loops and conditionals
- Jinja2 Tutorial - Part 3 - Whitespace control
- Jinja2 Tutorial - Part 4 - Template filters
- Jinja2 Tutorial - Part 5 - Macros
- Jinja2 Tutorial - Part 6 - Include and Import
- J2Live - Online Jinja2 Parser
Contents
- What are macros?
- Why and how of macros
- Adding parameters
- Macros for deeply nested structures
- Branching out inside macro
- Macros in macros
- Moving macros to a separate file
- Advanced macro usage
- Conclusion
- References
- GitHub repository with resources for this post
What are macros?
Macros are similar to functions in many programming languages. We use them to encapsulate logic used to perform repeatable actions. Macros can take arguments or be used without them.
Inside of macros we can use any of the Jinja features and constructs. Result of running macro is some text. You can essentially treat macro as Continue reading
Reducing Complexity through Interaction Surfaces
A recent paper on network control and management (which includes Jennifer Rexford on the author list—anything with Jennifer on the author list is worth reading) proposes a clean slate 4d approach to solving much of the complexity we encounter in modern networks. While the paper is interesting, it’s very unlikely we will ever see a clean slate design like the one described, not least because there will always be differences between what the proper splits are—what should go where.
There is one section of the paper that eloquently speaks to current architecture, however. The authors describe a situation where routing and packet filters are used together to prevent one set of hosts from reaching another set of hosts. Changes in the network, however, cause the packet filters to be bypassed, opening up communications between these two sets of hosts.
This is exactly the problem we so often face in network engineering today—overlapping systems used to solve a single problem do not pay attention to the same signals or information to do their jobs. So here’s a thought about an obvious way to reduce the complexity of your network—try to use one tool to do one job. Before the days of automation, this was much harder to do. There was no way to distribute QoS configurations, for instance, or access lists, much less what might be considered an “easy way.” Because of this, it made some kind of sense to use routing protocols as a sort of distributed database and policy engine to move filters and the like around.
Today, however, we have automation. Because of this, it makes more sense to use automation to manage as much data plane policy as you can, leaving the routing protocol to do its job—provide reachability across an ever-changing network. There are still things, like traffic steering and prefix distribution rules, which should stay inside routing. But when you put routing filters in place to solve a data plane problem, it might be worth thinking about whether that is the right thing to do any longer.
Automation, in this case, can change everything.