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Category Archives for "Networking"

Basing network security on IP addressing: Would it be worth it?

Why is it that over 90% of enterprises tell me that they expect to spend more on security over the next three years, and almost 60% say they expect to spend less on networking? We obviously think that network technology is getting more efficient, more competitive. Why isn’t that the case for security? The short answer is that enterprises have been chasing acronyms and not solutions.Acronym-chasing comes about because by nature, security is hard to plan for. The average network expert finds out there’s an issue because some higher-up reads or hears about a breach. Maybe they do a quick search, and they find out that what they really need is SASE. Or maybe they need SSE, which we’re told is SASE without SD-WAN. In any event, what happens is that there’s pressure to add this new thing on, and that creates another layer of protection...maybe.  Complication and cost? Surely.To read this article in full, please click here

EVPN-VXLAN Explainer 1 – Static VXLAN

EVPN-VXLAN Explainer 1 - Static VXLAN

In this series of blog posts I'm going to break down how to configure Aruba AOS-CX switches for VXLAN and EVPN, plus explain how to read the EVPN table and various 'show' commands.
In this first post I will look at VXLAN, its configuration and operation.

A note about EVPN-VXLAN

VXLAN: encapsulation type of 8 bytes, works at the data plane, concerned with the forwarding of packets.
Ethernet VPN (EVPN): Extension to BGP, works that the control plane, concerned with learning and advertising MAC/IP addresses.

Static VXLAN - Start Here

VXLAN configuration is one of the basic building blocks of a EVPN-VXLAN network, it is worth familiarising yourself with static VXLAN configuration, even if you are never going to use it.

Example Network

Figure 1 below shows a network comprised of three Aruba 6300 switches acting as VTEPs, with two customer VLANs, VLAN10 and VLAN 20, that are bound with VNI 1010 and VNI 1020 respectively across the VXLAN network.

EVPN-VXLAN Explainer 1 - Static VXLAN

VXLAN Configuration

Component parts of the configuration:

  1. Customer-side VLAN - carries the traffic to be encapsulated.
  2. An IP network between VTEPs (the underlay network)- there must be bi-directional connectivity between an IP address designated on the VTEP. Continue reading

Why Asking for Help is Not a Sign of Weakness

Asking for help can be difficult. It can be hard to admit that we need assistance, and sometimes pride gets in the way of our better judgment. We may worry that asking for help will make us seem weak or incompetent. However, this could not be further from the truth. Asking for help is actually a sign of strength. It shows that we are willing to admit when we need assistance and that we are not afraid to ask for support.

Why is it hard to ask for help?

There can be many reasons why it is hard to ask for help. We may worry that we will seem weak or incompetent. We may also feel like we need to be able to handle everything on our own. However, it is important to remember that asking for help is not a sign of weakness. It takes a lot of strength and courage to reach out for assistance, and there are many people who are willing to support us through whatever challenge we may be facing.

Situations where it’s perfectly acceptable – and even necessary – to ask for help

There is nothing wrong with asking for help. In fact, it Continue reading

US Tax Day 2022. How leaving it to the last day impacts tax sites

US Tax Day 2022. How leaving it to the last day impacts tax sites
“Our new Constitution is now established, and has an appearance that promises permanency; but in this world nothing can be said to be certain, except death and taxes.”
— Benjamin Franklin, in a letter to Jean-Baptiste Le Roy, 1789
US Tax Day 2022. How leaving it to the last day impacts tax sites

The famous expression highlighting that only “death and taxes” seem certain in life (something that goes back to the beginning of civilization and to Ancient Egypt) is on people’s minds during the month of April in the United States. This past Monday, April 18, 2022, was Tax Day. So, were US citizens procrastinators, leaving their federal (and state) tax returns to the last day? Traffic to tax-related official federal and state websites seems to show it: there was a spike of more than 470% on April 18.

Just for reference, we can see on Cloudflare Radar that Internet traffic in the US, from our perspective, wasn’t significantly impacted on Monday, April 18, although there was a clear peak, higher than in the previous 14 days, that night at 22:00 EST (that’s 02:00 UTC on April 19). So, traffic (that includes DNS and HTTP requests from our standpoint) was 18% higher compared to the same time on the previous Continue reading

Practical Python For Networking: 4.4 – SMS Alerting Full Example – Video

This lesson continues the SMS alerting example from lesson 4.3. Course files are in a GitHub repository: https://github.com/ericchou1/pp_practical_lessons_1_route_alerts Eric Chou is a network engineer with 20 years of experience, including managing networks at Amazon AWS and Microsoft Azure. He’s the founder of Network Automation Nerds and has written the books Mastering Python Networking and Distributed […]

The post Practical Python For Networking: 4.4 – SMS Alerting Full Example – Video appeared first on Packet Pushers.

Using whereis, whatis, and which to find out about commands on Linux

When you're trying to find your way around the Linux file system and want some information on specific commands, the whereis, whatis, and which commands can help. Each provides a different view of the command you're asking about. In this post, I'll compare these commands and explain what they tell us and what they don't tell us.which The which command is the simplest of the three. When you use it to ask about a Linux command, it will run down your search path looking for executable files by the name you specify. These can be commands that are available on your system as well as scripts. As long as the files provide you with execute privilege, they fit the bill. Here are some examples:To read this article in full, please click here

Using whereis, whatis, and which to find out about commands on Linux

When you're trying to find your way around the Linux file system and want some information on specific commands, the whereis, whatis, and which commands can help. Each provides a different view of the command you're asking about. In this post, I'll compare these commands and explain what they tell us and what they don't tell us.which The which command is the simplest of the three. When you use it to ask about a Linux command, it will run down your search path looking for executable files by the name you specify. These can be commands that are available on your system as well as scripts. As long as the files provide you with execute privilege, they fit the bill. Here are some examples:To read this article in full, please click here

AWS SAA vs. CLF – Can I skip one?

AWS are known for their famous highly demanded Solutions Architect Associate (SAA) Certificate, and many thinks that it is the first step with AWS and Cloud Computing, the question now is it?, or is there any step that should be taken before, like the AWS Cloud Practitioner CLF exam?.

in this blog post we will discover and compare the agenda and the main pillars each exam teach you, and see if it worth skipping CLF and start directly with SAA.

Cloud Concepts

Your very first chapter to start studying AWS CLF with will be the cloud concepts, this will give a general overview of what is the idea and concept of cloud computing, what would AWS provide regarding that, and are you about to experience.

Luckily this part is shared between both the exams of AWS CLF and SAA, and we’ll find a share for it here and there, to understand what we are about to start with such exams.

that makes them equal here, 1-1.

Security and Compliance

Having zero knowledge about cloud computing and the restrictions and differentiations that might occur with it, upon implementing a new network on the cloud for the first time will require Continue reading

OSPF Administrative Distance – How preferred is it

OSPF Administrative Distance, or OSPF AD, is the key of electing OSPF among other routing protocols (if existed) leading to the same target within the same routing table, in this blog post we will discover the basics and types of Administrative Distances for OSPF across multiple different platform.

Administrative Distance

For Cisco systems operating systems, regardless of their platforms, all the IOS-XE, IOS-XR, and NX-OS OS’s treats OSPF based on the “AD” which has the value of “110”.

Now the most important thing is not just to know the numerical value which will be useless without knowing its order of preference among the other routing protocol Administrative Distances.

OSPF AD with Cisco OS’s

The values will be as follows regarding the Static and Dynamic Routing Protocols:

  • Direct = 0
  • Static = 1
  • eBGP = 20
  • EIGRP = 90
  • OSPF 110
  • IS-IS = 115
  • RIP = 120
  • iBGP = 200

This Shows that OSPF routes to a specific target can be hidden if one of the dynamics (EIGRP or eBGP) routes was installed in the routing table, that also includes the Direct and Static as well.

Route Preference

Dealing with devices/platforms from Juniper Networks will get you to face and Continue reading

Network Digital Twins Work Best in PowerPoint

A friend of mine sent me the following question a few months ago:

I thought you might know the best way (currently) to create a digital clone of parts of a production network? The objective is to test changes against a test network as part of a CI/CD process. Ideally, there would be an automation that could replicate selected parts of a production network in a test network.

TL&DR: Sounds great, but you might be solving the wrong problem.

Read more …

Practical Python For Networking: 4.3 – SMS Alerting – First Example – Video

This lesson walks through the first example script for setting up SMS alerting. Course files are in a GitHub repository: https://github.com/ericchou1/pp_practical_lessons_1_route_alerts Eric Chou is a network engineer with 20 years of experience, including managing networks at Amazon AWS and Microsoft Azure. He’s the founder of Network Automation Nerds and has written the books Mastering Python […]

The post Practical Python For Networking: 4.3 – SMS Alerting – First Example – Video appeared first on Packet Pushers.

Privacy And Networking Part 2: Legal And Ethical Privacy

Given the arguments from the first article in this series, if privacy should be and is essential—what does the average network engineer do with this information? How does privacy impact network design and operations? To answer this question, we need to look at two other questions. First, what is private information, precisely? The network carries […]

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Practical Python For Networking: 4.2 – SMS Alerting – Python SDK And Environmental Variables – Video

This lesson describes how to install the Python SDK for Twilio so you can build SMS alerts. You can find the packages for this lesson in the GitHub repository that accompanies this course: https://github.com/ericchou1/pp_practical_lessons_1_route_alerts/tree/master/4_Packages Eric Chou is a network engineer with 20 years of experience, including managing networks at Amazon AWS and Microsoft Azure. He’s […]

The post Practical Python For Networking: 4.2 – SMS Alerting – Python SDK And Environmental Variables – Video appeared first on Packet Pushers.

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