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Category Archives for "Networking"

Using the btrfsck file-checing command on Linux

The btrfsck command is a filesystem-check command like fsck, but it works with the btrfs file system.First a little bit about btrfs. As the name implies, btrfs uses a B-tree data structure that is self-balancing and maintains sorted data, facilitating searches, sequential access, insertions, and deletions. It is also often referred to as the “better file system”. Oracle developed it and first used it about 15 years ago. By November 2013, it was declared adequately stable and began to be used by other distributions as well, and now its use is quite common.Benefits of btrfs The benefits of btrfs are impressive, although it’s still a work in progress and some concerns have kept it from playing a more dominant role on Linux systems. It keeps 2 copies of metadata on a volume, allowing for data recovery if and when the hard drive is damaged or suffers from bad sectors. It uses checksums and verifies them with each read. In addition, compared to ext4 volumes, btrfs does not require double the storage space to accommodate file versioning and history data.To read this article in full, please click here

Using the btrfsck file-checing command on Linux

The btrfsck command is a filesystem-check command like fsck, but it works with the btrfs file system.First a little bit about btrfs. As the name implies, btrfs uses a B-tree data structure that is self-balancing and maintains sorted data, facilitating searches, sequential access, insertions, and deletions. It is also often referred to as the “better file system”. Oracle developed it and first used it about 15 years ago. By November 2013, it was declared adequately stable and began to be used by other distributions as well, and now its use is quite common.Benefits of btrfs The benefits of btrfs are impressive, although it’s still a work in progress and some concerns have kept it from playing a more dominant role on Linux systems. It keeps 2 copies of metadata on a volume, allowing for data recovery if and when the hard drive is damaged or suffers from bad sectors. It uses checksums and verifies them with each read. In addition, compared to ext4 volumes, btrfs does not require double the storage space to accommodate file versioning and history data.To read this article in full, please click here

BGP Policies (Part 3)

At the most basic level, there are only three BGP policies: pushing traffic through a specific exit point; pulling traffic through a specific entry point; preventing a remote AS (more than one AS hop away) from transiting your AS to reach a specific destination. In this series I’m going to discuss different reasons for these kinds of policies, and different ways to implement them in interdomain BGP.

There are many reasons an operator might want to select which neighboring AS through which to send traffic towards a given reachable destination (for instance, 100::/64). Each of these examples assumes the AS in question has learned multiple paths towards 100::/64, one from each peer, and must choose one of the two available paths to forward along.

In the following network—

From AS65001’s perspective

Assume AS65001 is some form of content provider, which means it offers some service such as bare metal compute, cloud services, search engines, social media, etc. Customers from AS65006 are connecting to its servers, located on the 100::/64 network, which generates a large amount of traffic returning to the customers.
From the perspective of AS hops, it appears the path from AS65001 to AS65006 is the same length—if this Continue reading

Data center infrastructure spending still growing as cloud providers keep buying

Public cloud providers are quickly becoming the biggest buyers of data center infrastructure equipment, as purchasing of hardware and software both rebounded sharply in 2021, according to a recent report by Synergy Research Group.Overall spending grew by roughly 10% in year-on-year terms, reaching a total of $185 billion in 2021. The lion’s share of that spending was on hardware, according to Synergy, with 77% of the total spend going towards servers, storage and networking gear. Software, including operating systems, cloud management, virtualization and network security, made up the rest of the total.To read this article in full, please click here

Data center infrastructure spending still growing as cloud providers keep buying

Public cloud providers are quickly becoming the biggest buyers of data center infrastructure equipment, as purchasing of hardware and software both rebounded sharply in 2021, according to a recent report by Synergy Research Group.Overall spending grew by roughly 10% in year-on-year terms, reaching a total of $185 billion in 2021. The lion’s share of that spending was on hardware, according to Synergy, with 77% of the total spend going towards servers, storage and networking gear. Software, including operating systems, cloud management, virtualization and network security, made up the rest of the total.To read this article in full, please click here

Career Advice I’d Give To 20, 30 and 40-Something Year Old Me

Career Advice To 20-Something Year Old Me

Start that business. You have sufficient technical & business skills, and you can figure out what you don’t know. Take the chance now while you have little at risk.

You’re not the standard everyone else is supposed to live up to. Work on your own faults. They are legion.

Your boss is your boss for a reason. You’re not the boss for a reason, too. When you understand and accept those reasons, you’ll reduce the workplace friction you keep experiencing.

Meritocracy doesn’t mean what you think it means. Being good at your job doesn’t mean you deserve a promotion.

More responsibility comes easy, because no one wants it. More compensation comes hard, because everyone wants it.

Business owners who cheat their partners & customers will cheat their employees, too. Run at the first sign of dishonest business dealings.

Career Advice To 30-Something Year Old Me

Define your goals so you know when you’ve reached them. Otherwise, you’ll exhaust yourself with endless effort.

You are your own worst critic. Take yourself less seriously.

When you work for someone else, you are a replaceable component in a larger machine. This is by design.

You don’t Continue reading

Understanding Data Center Fabrics 08: Advanced Underlay Control Planes – Video

In this video, Russ White examines two advanced options for your underlay control plane: distoptflood and RIFT. He explores the basics of distopflood and RIFT, optimizations in distoptflood, centralized flooding, how RIFT works, and more. You can subscribe to the Packet Pushers’ YouTube channel for more videos as they are published. It’s a diverse a […]

The post Understanding Data Center Fabrics 08: Advanced Underlay Control Planes – Video appeared first on Packet Pushers.

Use zero trust to fight network technical debt

Zero trust (ZT) is a mindset and a method, not a technology. The current push to adopt ZT is driven by an urgent and growing need to make a major leap forward in risk management and attack containment in enterprise networks, a need driven home by every successive wave of ransomware. IT can use the urgency of moving to ZT to root out some of the technical debt in the environment. Specifically, it can be a catalyst to find areas exempted from network and network security standards and bring them up to date under the new paradigm of zero trust.No more exempting network components from access-control roles In a ZT environment, the network not only doesn’t trust a node new to it, but it also doesn’t trust nodes that are already communicating across it. When a node is first seen by a ZT network, the network will require that the node go through some form of authentication and authorization check. Does it have a valid certificate to prove its identity? Is it allowed to be connected where it is based on that identity? Is it running valid software versions, defensive tools, etc.? It must clear that hurdle before being Continue reading

Use zero trust to fight network technical debt

Zero trust (ZT) is a mindset and a method, not a technology. The current push to adopt ZT is driven by an urgent and growing need to make a major leap forward in risk management and attack containment in enterprise networks, a need driven home by every successive wave of ransomware. IT can use the urgency of moving to ZT to root out some of the technical debt in the environment. Specifically, it can be a catalyst to find areas exempted from network and network security standards and bring them up to date under the new paradigm of zero trust.No more exempting network components from access-control roles In a ZT environment, the network not only doesn’t trust a node new to it, but it also doesn’t trust nodes that are already communicating across it. When a node is first seen by a ZT network, the network will require that the node go through some form of authentication and authorization check. Does it have a valid certificate to prove its identity? Is it allowed to be connected where it is based on that identity? Is it running valid software versions, defensive tools, etc.? It must clear that hurdle before being Continue reading

Combining BGP and IGP in an Enterprise Network

Syed Khalid Ali left the following question on an old blog post describing the use of IBGP and EBGP in an enterprise network:

From an enterprise customer perspective, should I run iBGP or iBGP+IGP (OSPF/ISIS/EIGRP) or IGP while doing mutual redistribution on the edge routers. I was hoping if you could share some thoughtful insight on when to select one over the another?

We covered tons of relevant details in the January 2022 Design Clinic, here’s the CliffNotes version. Keep in mind that the road to hell (and broken designs) is paved with great recipes and best practices, and that I’m presenting a black-and-white picture because I don’t feel like transcribing the discussion we had into an oversized blog post. People wrote books on this topic; I’m pretty sure you can search for Russ White and find a few of them.

Finally, there’s no good substitute for understanding how things work (which brings me to another webinar ;).

Read more …

Combining BGP and IGP in an Enterprise Network

Syed Khalid Ali left the following question on an old blog post describing the use of IBGP and EBGP in an enterprise network:

From an enterprise customer perspective, should I run iBGP, iBGP+IGP (OSPF/ISIS/EIGRP), or IGP with mutual redistribution on the edge routers? I was hoping you could share some thoughtful insight on when to select one over the other.

We covered many relevant details in the January 2022 Design Clinic; here’s the CliffNotes version. Remember that the road to hell (and broken designs) is paved with great recipes and best practices and that I’m presenting a black-and-white picture because I don’t feel like transcribing our discussion into an oversized blog post. People wrote books on this topic; search for “Russ White books” to find a few.

Finally, there’s no good substitute for understanding how things work (which brings me to another webinar ;).

Read more …

Automation 13. Real-life Example of a Python Automation for a Network Audit with Nornir and Scrapli

Hello my friend,

Today we are going to discuss a real-life experience, how network automation helped us to save a lot of time and significantly improve a quality of the medium size data centre. You will learn about the problem, which audit was to solve and how Python leveraging Nornir and Scrapli solved it.



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Can Automation Help with Audits?

We, humans, are incredible creatures. We can create. We can write songs and compose music; we can invent new drugs and find new materials. We can develop new software and tools. However, in order to be able to do that, we need to have a free time and not to worry about anything. That’s why we need to rely on different tools, which can do routine tasks requiring a lot of concentration at least as good as we, humans, can. Probably, even better than we. Audit is one of such tasks, and in IT world it definitely Continue reading

Understanding Data Center Fabrics 07: Link State Protocol In The Underlay – Video

Episode seven continues a discussion of fabric underlays by looking at the use of link-state protocols instead of BGP. Network architect and author Russ White covers: -Which link state protocol (IS-IS or OSPF) to choose -Russ’s reasons for preferring IS-IS -IS-IS efficiencies for packet formats and autoconfiguration -Resource recommendations for learning IS-IS -Scale and flooding […]

The post Understanding Data Center Fabrics 07: Link State Protocol In The Underlay – Video appeared first on Packet Pushers.

VPP Configuration – Part1

VPP

About this series

I use VPP - Vector Packet Processor - extensively at IPng Networks. Earlier this year, the VPP community merged the Linux Control Plane plugin. I wrote about its deployment to both regular servers like the Supermicro routers that run on our AS8298, as well as virtual machines running in KVM/Qemu.

Now that I’ve been running VPP in production for about half a year, I can’t help but notice one specific drawback: VPP is a programmable dataplane, and by design it does not include any configuration or controlplane management stack. It’s meant to be integrated into a full stack by operators. For end-users, this unfortunately means that typing on the CLI won’t persist any configuration, and if VPP is restarted, it will not pick up where it left off. There’s one developer convenience in the form of the exec command-line (and startup.conf!) option, which will read a file and apply the contents to the CLI line by line. However, if any typo is made in the file, processing immediately stops. It’s meant as a convenience for VPP developers, and is certainly not a useful configuration method for all but the simplest topologies.

Luckily, VPP comes Continue reading

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