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Category Archives for "Networking"

Using logger on Linux

The logger command provides an easy way to add log files to /var/log/syslog -- from the command line, from scripts or from other files. In today's post, we'll take a look at how it works.How easy is easy? This easy. Just type logger <message> on the command line and your message will be added to the end of the /var/log/syslog file.$ logger comment to be added to log $ tail -1 /vvar/log/syslog May 21 18:02:16 butterfly shs: comment to be added to log Command output You can also add the output from commands by enclosing the commands in backticks.$ logger `who` $ tail -1 /var/log/syslog May 21 18:02:43 butterfly shs: shs pts/0 2018-05-21 15:57 (192.168.0.15) Content from a file The contents of text files can be added by using the -f option. Put the name of the file to be added to the log following the -f option as shown below.To read this article in full, please click here

How to use logger on Linux

The logger command provides an easy way to add log files to /var/log/syslog — from the command line, from scripts, or from other files. In today's post, we'll take a look at how it works.How easy is easy? This easy. Just type logger <message> on the command line and your message will be added to the end of the /var/log/syslog file.$ logger comment to be added to log $ tail -1 /vvar/log/syslog May 21 18:02:16 butterfly shs: comment to be added to log Command output You can also add the output from commands by enclosing the commands in backticks.$ logger `who` $ tail -1 /var/log/syslog May 21 18:02:43 butterfly shs: shs pts/0 2018-05-21 15:57 (192.168.0.15) [ Two-Minute Linux Tips: Learn how to master a host of Linux commands in these 2-minute video tutorials ] Content from a file The contents of text files can be added by using the -f option. Put the name of the file to be added to the log following the -f option as shown below.To read this article in full, please click here

22 essential security commands for Linux

There are many aspects to security on Linux systems – from setting up accounts to ensuring that legitimate users have no more privilege than they need to do their jobs. This is look at some of the most essential security commands for day-to-day work on Linux systems.To read this article in full, please click here(Insider Story)

22 essential Linux security commands

There are many aspects to security on Linux systems – from setting up accounts to ensuring that legitimate users have no more privilege than they need to do their jobs. This is look at some of the most essential security commands for day-to-day work on Linux systems.To read this article in full, please click here(Insider Story)

22 essential security commands for Linux

There are many aspects to security on Linux systems – from setting up accounts to ensuring that legitimate users have no more privilege than they need to do their jobs. This is look at some of the most essential security commands for day-to-day work on Linux systems.sudo Running privileged commands with sudo  – instead of switching user to root  – is one essential good practice as it helps to ensure that you only use root privilege when needed and limits the impact of mistakes. Your access to the sudo command depends on settings in the /etc/sudoers and /etc/group files. [ Two-Minute Linux Tips: Learn how to master a host of Linux commands in these 2-minute video tutorials ] $ sudo adduser shark Adding user `shark' ... Adding new group `shark' (1007) ... Adding new user `shark' (1007) with group `shark' ... Creating home directory `/home/shark' ... Copying files from `/etc/skel' ... Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully Changing the user information for shark Enter the new value, or press ENTER for the default Full Name []: shark Room Number []: Work Phone []: Home Phone []: Other []: Is the information correct? [Y/n] Y If you run sudo Continue reading

22 essential Linux security commands

There are many aspects to security on Linux systems – from setting up accounts to ensuring that legitimate users have no more privilege than they need to do their jobs. This is look at some of the most essential security commands for day-to-day work on Linux systems.sudo Running privileged commands with sudo  – instead of switching user to root  – is one essential good practice as it helps to ensure that you only use root privilege when needed and limits the impact of mistakes. Your access to the sudo command depends on settings in the /etc/sudoers and /etc/group files. [ Two-Minute Linux Tips: Learn how to master a host of Linux commands in these 2-minute video tutorials ] $ sudo adduser shark Adding user `shark' ... Adding new group `shark' (1007) ... Adding new user `shark' (1007) with group `shark' ... Creating home directory `/home/shark' ... Copying files from `/etc/skel' ... Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully Changing the user information for shark Enter the new value, or press ENTER for the default Full Name []: shark Room Number []: Work Phone []: Home Phone []: Other []: Is the information correct? [Y/n] Y If you run sudo Continue reading

22 essential Linux security commands

There are many aspects to security on Linux systems – from setting up accounts to ensuring that legitimate users have no more privilege than they need to do their jobs. This is look at some of the most essential security commands for day-to-day work on Linux systems.sudo Running privileged commands with sudo  – instead of switching user to root  – is one essential good practice as it helps to ensure that you only use root privilege when needed and limits the impact of mistakes. Your access to the sudo command depends on settings in the /etc/sudoers and /etc/group files. [ Two-Minute Linux Tips: Learn how to master a host of Linux commands in these 2-minute video tutorials ] $ sudo adduser shark Adding user `shark' ... Adding new group `shark' (1007) ... Adding new user `shark' (1007) with group `shark' ... Creating home directory `/home/shark' ... Copying files from `/etc/skel' ... Enter new UNIX password: Retype new UNIX password: passwd: password updated successfully Changing the user information for shark Enter the new value, or press ENTER for the default Full Name []: shark Room Number []: Work Phone []: Home Phone []: Other []: Is the information correct? [Y/n] Y If you run sudo Continue reading

Rate Limiting: Delivering more rules, and greater control

Rate Limiting: Delivering more rules, and greater control

With more and more platforms taking the necessary precautions against DDoS attacks like integrating DDoS mitigation services and increasing bandwidth at weak points, Layer 3 and 4 attacks are just not as effective anymore. For Cloudflare, we have fully automated Layer 3/4 based protections with our internal platform, Gatebot. In the last 6 months we have seen a large upward trend of Layer 7 based DDoS attacks. The key difference to these attacks is they are no longer focused on using huge payloads (volumetric attacks), but based on Requests per Second to exhaust server resources (CPU, Disk and Memory). On a regular basis we see attacks that are over 1 million requests per second. The graph below shows the number of Layer 7 attacks Cloudflare has monitored, which is trending up. On average seeing around 160 attacks a day, with some days spiking up to over 1000 attacks.

Rate Limiting: Delivering more rules, and greater control

A year ago, Cloudflare released Rate Limiting and it is proving to be a hugely effective tool for customers to protect their web applications and APIs from all sorts of attacks, from “low and slow” DDoS attacks, through to bot-based attacks, such as credential stuffing and content scraping. We’re pleased about the Continue reading

Research: Robustness in Complex Systems

While the network engineering world tends to use the word resilience to describe a system that will support rapid change in the real world, another word often used in computer science is robustness. What makes a system robust or resilient? If you ask a network engineer this question, the most likely answer you will get is something like there is no single point of failure. This common answer, however, does not go “far enough” in describing resilience. For instance, it is at least sometimes the case that adding more redundancy into a network can actually harm MTTR. A simple example: adding more links in parallel can cause the control plane to converge more slowly; at some point, the time to converge can be reduced enough to offset the higher path availability.

In other cases, automating the response to a change in the network can harm MTTR. For instance, we often nail a static route up and redistribute that, rather than redistributing live routing information between protocols. Experience shows that sometimes not reacting automatically is better than reacting automatically.

This post will look at a paper that examines robustness more deeply, Robustness in Complexity Systems,” by Steven Gribble. While this Continue reading

Network Break 185: HPE Acquires Plexxi; New Batch Of Cisco Security Advisories

Take a Network Break! In this week’s episode we examine why HPE acquired Plexxi, dig into the latest batch of security advisories from Cisco, and discuss Intel’s reference architecture for new uCPE gear.

The Appropriations Committee in the U.S. Congress wants to keep up sanctions pressure against ZTE, AWS adds Verizon as a customer, and a new DDoS attack technique looks to thwart a common filter.

Toshiba clears its last hurdle to sell is semiconductor business, Cisco posts a positive third quarter, and Symantec announces an internal audit into its financial results.

Sponsor: ThousandEyes

ThousandEyes gives you performance visibility from every user to every app over any network, both internal and external, so you can smoothly migrate to the cloud, transform your WAN, troubleshoot faster and deliver exceptional user experiences. Sign up for a free account at thousandeyes.com/packetpushers and choose a free ThousandEyes t-shirt.

Sponsor: Cisco Systems

Find out how Cisco and its trusted partners Equilibrium Security and ePlus/IGX can help your organization tackle the General Data Protection Regulation, or GDPR. Tune into Packet Pushers Priority Queue episode 147 to get practical insights on how to get your arms around these wide-ranging rules.

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HPE Acquires Plexxi For HCI, Continue reading

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