There are many ways to remove duplicate lines from a text file on Linux, but here are two that involve the awk and uniq commands and that offer slightly different results.Remove duplicate lines with awk
The first command we'll examine in this post is a very unusual awk command that systematically removes every line in the file that is encountered more than once. It leaves the first instance of the line intact, but "remembers" it and removes any duplicates encountered afterwards.Here's an example. Initially, the file looks like this:To read this article in full, please click here
The relatively stable world of enterprise networking has undergone quite a bit of upheaval over the past few years. As a result, networking professionals with traditional job titles have assumed new responsibilities, and entirely new job titles have emerged.Key trends reshaping the jobs of network professionals include increased adoption of cloud services; the push for more automation of business processes; and the rise of technologies such as software-defined networking (SDN), SD-WAN, Internet of Things (IoT) , secure access service edge (SASE), Zero Trust Network Access (ZTNA) and edge computing.To read this article in full, please click here
In a zero-trust environment, trust is not static. Behavior has to be visible for trust to persist.One of the most important differences between old thinking on networking and the zero-trust mindset is the inversion of thinking on trust. Pre-ZT, the assumption was this: Once you get on the network, you are assumed to be allowed to use it any way you want until something extraordinary happens that forces IT to shut you down and remove your access. You are assumed broadly trustworthy, and confirming that status positively is very rare. It is also very rare to have that status revoked.To read this article in full, please click here
Cloud NGFW for AWS enables organizations to shift security responsibility to Palo Alto, allowing them to speed cloud innovation while remaining secure, the vendor says.
You’ve just been given the task of solving a network problem that has been unresolved for many months. Where do you start? Is it a solvable problem or is it just the way the network works? Maybe you’ve encountered a limitation on how network protocols function. What follows is an account of just such a problem that stumped many good network engineers for months and how it was resolved by NetCraftsmen’s Samuel Bickham. It may provide tips for solving problems you face down the road. As Bickham says, “Troubleshooting is kinda like a magic trick: It’s impressive until it’s explained.”A customer contacted NetCraftsmen to ask if we could diagnose a networking problem that affected only a few applications and a subset of employees on an intermittent basis.To read this article in full, please click here
Aruba Networks is expanding its Edge Services Platform to better manage and automate the operation of far-flung distributed enterprise networks.Hewlett Packard Enterprise’s network subsidiary rolled out NetConductor, a cloud-based service that Aruba says will help enterprises centrally manage the security of distributed networks while simplifying policy provisioning and automating the orchestration of network configurations in wired, wireless, and WAN infrastructures.What is SDN and where it’s going
NetConductor is a service delivered by Aruba Central, the vendor’s core cloud-based management platform and works by delivering an EVPN, VXLAN-based network overlay across a customer’s wired and wireless networks offering a much more unified and simplified view of the network to the networking team, according to Larry Lunetta, vice president of wireless local area network and security solutions marketing at Aruba.To read this article in full, please click here
Arista will soon roll out a cloud-based package of edge networking and security services for small to medium sized businesses that have limited IT management resources.Arista’s Cognitive Unified Edge (CUE) service is a turnkey package of new and existing Arista network and security gear that can be installed on a customer site and be controlled via a single dashboard on by the company’s core CloudVision management platform. How to choose an edge gateway
CloudVision provides wired and wireless visibility, automation, orchestration, provisioning, telemetry, and analytics across the data center, campus, and IoT devices on edge networks. CloudVision’s network information can be utilized by Arista networking partners such as VMware and Microsoft.To read this article in full, please click here
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
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
The Spanning Tree Protocol, sometimes just referred to as Spanning Tree, is the Waze or MapQuest of modern Ethernet networks, directing traffic along the most efficient route based on real-time conditions.Based on an algorithm created by American computer scientist Radia Perlman while she was working for Digital Equipment Corporation (DEC) in 1985, the primary purpose of Spanning Tree is to prevent redundant links and the looping of communication pathways in complex network configurations. As a secondary function, Spanning Tree can route packets around trouble spots to ensure that communications are able to wind through networks that might be experiencing disruptions.To read this article in full, please click here
Wi-Fi 6, also known as 802.11ax, was officially certified in 2020 and has quickly become the de facto standard for wireless LAN (WLAN), superseding Wi-Fi 5 (802.11ac). Wi-Fi 6 delivers improved performance, extended coverage, and longer battery life compared to Wi-Fi 5.Wi-Fi 6 was originally designed to address bandwidth problems associated with dense, high-traffic environments such as airports, stadiums, trains, and offices. However, the explosion of IoT devices that need to connect wirelessly to edge devices, and the ever-increasing bandwidth needs of new data-thirsty applications has rendered Wi-Fi 6 not exactly obsolete on arrival, but certainly not sufficient for some use cases.To read this article in full, please click here
How many people on social media have friends only in their home city? Probably not very many, so we shouldn’t think that when Meta or others deploy a metaverse, the inhabitants will all be drawn from the same place.To be successful, a metaverse has to support dispersed users, and the more successful it is, the more its users can be expected to be dispersed over a wider geography. Today, metro, but tomorrow the world. If, as the metaverse spreads out, latency issues destroy the synchronized behavior of the avatars, then it will lose realism and at some point that loss would constrain growth. We already know how to control access latency, but how do we control massive-metaverse latency? Answer: With Massive Metaverse Meshing.To read this article in full, please click here
How many people on social media have friends only in their home city? Probably not very many, so we shouldn’t think that when Meta or others deploy a metaverse, the inhabitants will all be drawn from the same place.To be successful, a metaverse has to support dispersed users, and the more successful it is, the more its users can be expected to be dispersed over a wider geography. Today, metro, but tomorrow the world. If, as the metaverse spreads out, latency issues destroy the synchronized behavior of the avatars, then it will lose realism and at some point that loss would constrain growth. We already know how to control access latency, but how do we control massive-metaverse latency? Answer: With Massive Metaverse Meshing.To read this article in full, please click here
Cisco has added new features to its core cloud and computing packages to better manage and support distributed applications.The enhancements affect Cisco’s Intersight cloud management system, UCS X-Series server and HyperFlex hyperconverged system.The idea is to provide tools that offer flexibility and manageability while increasing performance and reducing the costs of modern cloud-based apps and workloads, said DD Dasgupta, vice president of Cisco’s Cloud & Compute Product Management group. Cisco is extending its Intersight support for Kubernetes, which had managed only Cisco Kubernets and only on-premises. The upgrade, Intersight Kubernetes Service Attached Clusters, provides a single place for IT pros to look at and manage all their Kubernetes clusters, including those running on Microsoft Azure and AWS cloud platforms, with plans to add Google Cloud support in the future.To read this article in full, please click here
Exacerbated by the pandemic, the chip shortage neared crisis proportions at the start of the year. Network vendors calculated the impact on their businesses in recent earnings reports: Cisco's current product backlog is at nearly $14 billion, Juniper reported a backlog of $1.8 billion, and Arista said that lead times on sales are 50 to 70 weeks.Then Russia invaded Ukraine, putting even more stress on the global supply chain. Ukraine manufactures 70% of the world's neon gas, which is needed for the industrial lasers used in semiconductor manufacturing, according to research firm TrendForce.To read this article in full, please click here
There are many options for backing up databases, and what’s best varies from database to database and how it’s delivered. Here are recommendations for seven of them, with a glimpse at how the options were chosen to help inform your decision making.Oracle
Oracle has many options for backup, but the official answer for backing Oracle would be Recovery Manager, or RMAN, which is also the name of the actual command that invokes it. Among many options, RMAN supports an image option that can merge older incremental backups into full backups, which would give you multiple recovery points without having to make multiple full backups. That’s an efficient dump and sweep option, but challenge is you need enough disk space to store a full backup and a series of incrementals. If you’re short on disk space, you can also use the SQL command alter database begin backup before you back up and alter database end backup when you’re done. This will allow you to use whatever backup method you choose. Oracle on Windows also integrates with Volume Shadow Copy Services (VSS), allowing you to perform hot backups without having to script at all. The RMAN image option with a Continue reading
Network Access Control (NAC) is a cybersecurity technique that prevents unauthorized users and devices from entering private networks and accessing sensitive resources. Also known as Network Admission Control, NAC first gained a foothold in the enterprise in the mid-to-late 2000s as a way to manage endpoints through basic scan-and-block techniques.As knowledge workers became increasingly mobile, and as BYOD initiatives spread across organizations, NAC solutions evolved to not only authenticate users, but also to manage endpoints and enforce policies.How NAC works
NAC tools detect all devices on the network and provide visibility into those devices. NAC software prevents unauthorized users from entering the network and enforces policies on endpoints to ensure devices comply with network security policies. NAC solutions will, for instance, make sure that the endpoint has up-to-date antivirus and anti-malware protections.To read this article in full, please click here
For the most part the dire warnings about running out of internet addresses have ceased because, slowly but surely, migration from the world of Internet Protocol Version 4 (IPv4) to IPv6 has begun, and software is in place to prevent the address apocalypse that many were predicting.But before we see where are and where we’re going with IPv6, let’s go back to the early days of internet addressing.What is IPv6 and why is it important?
IPv6 is the latest version of the Internet Protocol, which identifies devices across the internet so they can be located. Every device that uses the internet is identified through its own IP address in order for internet communication to work. In that respect, it’s just like the street addresses and zip codes you need to know in order to mail a letter.To read this article in full, please click here
The fail2ban tool in Linux monitors system logs for signs of attacks, putting offending systems into what is called "jail", and modifying firewall settings. It shows what systems are in jail at any given time, and requires root access to configure and view findings. It's generally used on Linux servers.fail2ban primarily focuses on SSH attacks, but can be configured to look for other kinds of attacks as well.How to install fail2ban on Fedora 34
To prepare for installing fail2ban, it's a good idea to update the system first:$ sudo dnf update && sudo dnf upgrade -y
Then install fail2ban and verify its presence on your system with commands like these:To read this article in full, please click here
Network-as-a-service (NaaS) is gaining momentum, providing a subscription-based model that eliminates the need for enterprises to own, build, and maintain their own network infrastructure. By replacing conventional hardware-centric VPNs, firewall appliances, load balancers, and MPLS connections, NaaS technology promises adopters the ability to rapidly scale up and down in lockstep with demand while eliminating hardware costs and bolstering network security and service levels.To read this article in full, please click here