Creating a quick calculation function on Linux

Anytime you're planning to do a lot of calculations on a Linux system, you can use the power of bash to create a quick function and then use it repeatedly to do the calculations for you. In this post, we'll look at how this trick works and what you need to be aware of to ensure that your calculations are correct.Let's start with this mathematical function as an example:$ ? () { echo "$*" | bc ; } Troubleshooting your bash scripts in Linux   This command sets up a function that will pass the values and mathematical operators that you provide as arguments to the bc calculator command. Note that to call the function, you simply type a "?" followed by the arguments. In the first example below, the arguments are 1, followed by the multiplication character "*", followed by a 2, a "+" sign and a 3. The result is 5.To read this article in full, please click here

Microsoft shifts SONiC development to the Linux Foundation

The enhancement and adoption of SONiC, the open-source network operating system, could accelerate now that its development has been given over to the the Linux Foundation, experts say.Software for Open Networking in the Cloud had been overseen by Microsoft, which has now ceded that role to the Linux Foundation. [ Get regularly scheduled insights by signing up for Network World newsletters. ] The shift could result in the scale and use of the NOS grow as the foundation provides a trusted hub for over 450,000 developers to code, manage and advance open technology projects.To read this article in full, please click here

Microsoft shifts SONiC network operating system development to the Linux Foundation

The enhancement and adoption of SONiC, the open-source network operating system, could accelerate now that its development has been given over to the the Linux Foundation, experts say.Software for Open Networking in the Cloud had been overseen by Microsoft, which has now ceded that role to the Linux Foundation. [ Get regularly scheduled insights by signing up for Network World newsletters. ] The shift could result in the scale and use of the NOS grow as the foundation provides a trusted hub for over 450,000 developers to code, manage and advance open technology projects.To read this article in full, please click here

DMVPN vs MPLS VPN

DMVPN – Dynamic Multipoint VPN and MPLS VPN are two of the most popular VPN mechanisms. In this post, we will look at DMVPN vs MPLS VPN comparison, from many different aspects. At the end of this post, you will be more comfortable positioning these private VPN mechanisms.

DMVPN vs MPLS VPN

When we compare the two protocols, we look at many different aspects. For this comparison, I think very first we should say that DMVPN is a Cisco preparatory tunnel-based VPN mechanism but MPLS VPN is standard-based, RFC 2547, non-tunnel based VPN mechanism. Although, whether MPLS LSP is a tunnel or not is an open discussion in the networking community, we won’t start that discussion here again.

DMVPN and MPLS VPN over the Internet

Another important consideration for MPLS VPN vs DMVPN is, that DMVPN can be set up over the Internet but MPLS VPN works over private networks, Layer 2 or Layer 3 based private networks. DMVPN tunnels can come up over the Internet and inside the tunnels routing protocols can run to advertise the Local Area Networks subnets.

But MPLS requires Private network underlay.

DMVPNN vs MPLS

Figure – DMVPN Networks can run over Internet or Private Networks 

 

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Deep dive on Ansible VScode extension

Ansible as part of the Red Hat Ansible Automation Platform continues to grow and mature. Recent enhancements include Ansible Content Collections, automation execution environments, and an increasing list of integrations using plugins and modules. It is more important than ever that both new and experienced content creators have access to tools that help them write better content faster. The newly created Ansible Devtools initiative focuses on developing and enhancing tools like ansible-navigator, Ansible VScode extension, ansible-lint and so on to help ease the Ansible automation content creator experience. In this blog, we will do a deep dive into the Ansible VSCode extension, giving an overview of how it works and the initial setup required to get it working after installation.

 

Evolution

The Ansible VSCode extension was initially a fork of Tomasz Maciążek’s VSCode extension. After the fork, the server and client-side code were decoupled into their own separate repositories to allow independent releases for both server and client.

  1. Ansible language server
  2. Ansible VSCode extension 

The Ansible Language Server is released as a node module on the npm repository, allowing it to be reused by other editors supporting language server protocol, while Continue reading

What is Ethernet?

Ethernet is one of the original networking technologies, having been invented nearly 50 years ago. And yet, because of the simplicity by which the communications protocol can be deployed and its ability to incorporate modern advancements without losing backwards compatibility, Ethernet continues to reign as the de facto standard for computer networking.At its core, Ethernet is a protocol that allows computers (from servers to laptops) to talk to each other over wired networks that use devices like routers, switches and hubs to direct traffic. Ethernet works seamlessly with wireless protocols, too.Its ability to work within almost any environment has led to its universal adoption around the world. This is especially true because it allows organizations to use the same Ethernet protocol in their local area network (LAN) and their wide-area network (WAN). That means that it works well in data centers, in private or internal company networks, for internet applications and almost anything in between. It can even support the most complex forms of networking, like virtual private networks (VPNs) and software-defined networking deployments.To read this article in full, please click here

How SASE uses AI

Secure access service edge, or SASE, combines networking and security into a cloud-based service, and it’s growing fast. According to Gartner projections, enterprise spending on SASE will hit almost $7 billion this year, up from under $5 billion in 2021. Gartner also predicts that more than 50% of organizations will have strategies to adopt SASE by 2025, up from less than 5% in 2020.To read this article in full, please click here

IS-IS Routing Ptrotocol

IS-IS is a link-state routing protocol, similar to OSPF. If you are looking for Service Provider grade, MPLS Traffic Engineering support, and extendible routing protocol for easier future migration then the only choice is IS-IS.

Commonly used in Service Providers, Datacenter (as an underlay), and some large Enterprise networks.

IS-IS Routing Protocol in Networking

IS-IS works based on TLV format. TLVs provide extensibility to the IS-IS protocol.

IS-IS TLV Codes – Specified in RFC 1195

IS-IS TLV format

 

You don’t need totally different protocol to support new extensions. In IS-IS IPv6, MTR and many other protocols just can be used with additional TLVs.

1. IPv6 Address Family support (RFC 2308)
2. Multi-Topology support (RFC 5120)
3. MPLS Traffic Engineering (RFC 3316)
IS-IS is a Layer 2 protocol and is not encapsulated in IP, thus it is hard if not impossible to attack Layer2 networks remotely, IS-IS is considered more secure than OSPF.
is-is dataplane

IS-IS uses a NET (Network Entity Title) address similar to OSPF Router ID.

IP support to IS-IS is added by the IETF after ISO invented it for the CLNS. If IS-IS is used together with IP, it is called Integrated IS-IS.

IS-IS doesn’t require an IP address for the neighborship.

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Mitigate Supply-Chain Attacks With Microsegmentation And ZTNA

This article originally appeared on Packet Pushers Ignition on January 12, 2021. In broad terms, the SolarWinds attack is a standard (though well-executed) supply-chain compromise that breaches a trusted source of software, hardware, or services to gain entry into an organization’s internal infrastructure. Once inside, it spreads to other systems, installs additional tools, compromises user […]

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OSPF Configuration – A sample template on multi-vendor routers

There are commons and differences to the time when it comes to configuring an OSPF routing protocol on a router you manage, based on the router’s manufacturer.

We will take a look at the basic sample of configuring OSPF on Cisco IOS-XE and Juniper’s JunOS operation systems.

OSPF on Cisco IOS-XE

With ios-xe we start configuring OSPF by mentioning the numerical value of the:

OSPF Process ID

And what that does mean is just a number to isolate some hierarchical designs of the OSPF process on the router of cisco.

Does it have to be matched on both the peering ends?, the answer is NO

Does it affect some priorities in some OSPF election processes?, the answer is also NO

Is it that mandatory?, well based on that “OS” it is, but it is not a general OSPF concept?

As it is missing with the other vendors!!

That makes the first line of configuration look like this:

        OERouter1(config)#router OSPF [Process ID]

i.e. “OERouter1(config)#router ospf 10

OSPF Network Advertisement

the later step after getting into the hierarchical mode of OSPF, specifying the process ID as well, is to advertise the networks.

these networks Continue reading

Practical Python For Networking: 4.1 – SMS Alerting – Introduction To Twilio – Video

This lesson walks through how to use a Python script to send alerts via text messages using Twilio. Course files and code samples for this and the other lessons 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. […]

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OSPF Protocol Basic Overview

What is OSPF

Language-wise it stands for Open Shortest Path First, and Family wise it belongs to the Link-State Interior Gateway Dynamic Routing Protocols.

done with the CV yet?, OSPF is an open standard internal routing protocol that is supported across all the different vendors manufacturing networking platforms.

In this article, we will review the basics and specs of this protocol, and see its own unique features.

OSPF Neighbor States

As a start, the OSPF routing protocol uses a multicast hello message that is destined to the OSPF Multicast address of 244.0.0.5 seeking any possible other OSPF routers in the area.

This message keeps repeating every 10 seconds by default, and that will be out of the interfaces that announced an OSPF configuration, which depends on how you configured it + the vendor-specific configuration template.

Upon receiving a multicast hello message from another router we already sent it a hello message earlier, and that should be within the dead timer of 40 seconds maximum (by default).

An OSPF neighbor process will start by:

  • Init:

    • at the moment of confirmation that a bidirectional multicast hello has initiated
  • 2-Way:

    • communication from the 2 parts has successfully occurred
  • ExStart:

BGP Authentication? User TCP/AO Instead of MD5! With Melchior Aelmans – Video

Melchior Aelmans of Juniper Networks explains what TCP/AO (RFC5925) is to Packet Pushers podcast host Ethan Banks. Then we get a Junos-based demo of TCP/AO in action authenticating a BGP session as an alternative to MD5. https://packetpushers.net https://datatracker.ietf.org/doc/html/rfc5925 Tweets by MelchiorAelmans About You can subscribe to the Packet Pushers’ YouTube channel for more videos as […]

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