Enterprise IT

New Relic APM on Fedora/CentOS/RedHat with SELinux Enforcing: Solved

I found the solution for getting the New Relic APM Agent to run on a CentOS 7 system with SELinux Enforcing. The only SELinux modification you have to make is to change the context of the log file directory /var/log/newrelic. You can temporarily make these changes with the chcon command: Kill any running instances of …

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Internet Service Comparison: Spectrum Cable Modem vs AT&T Fiber

I’m moving to a new address in Central Florida which has multiple Internet Service Providers (ISPs) available. Spectrum (formerly BrightHouse) provides speeds up to 100Mbps via cable modem. AT&T just installed fiber in the neighborhood, so I was excited to find out what they would offer. Spectrum Cable Internet Here’s a cost breakdown by service: …

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Configure CentOS/RedHat VMs with Kickstart files on Virtualbox

Kickstart is a type of file that’s used to automatically install RedHat or CentOS Linux on a physical or virtual server. If you are managing more than a few servers, it’s a good idea to configure the servers via kickstart files instead of logging in and configuring each one manually. However, some unfortunate choices were …

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Upgrade Ubiquiti UniFi Access Points (WAP) now to avoid KrackAttack

On October 15, 2017, security researcher Mathy Vanhoef announced the discovery of KrackAttacks, a serious flaw in the WPA2 encryption protocol that encrypts most WiFi connections. Using this method, an attacker can decrypt traffic from almost any wireless access point (WAP) and clients. Every WiFi access point will need to be upgraded with patch that prevents …

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Warning: CentOS/RedHat 7.4 installs FreeRADIUS 3 with breaking changes

When you run yum upgrade on a CentOS/RedHat 7 instance, you will be upgraded to 7.4. If you have a FreeRADIUS server, you will be upgraded from version 2 to 3, and your server will likely stop authenticating! Good times! Fortunately, the solution was not complicated for us, because we had good documentation. Symptoms Your …

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Managing persistent disks on Google Compute Engine

It can confusing when you have multiple persistent disks on an instance running on Google Compute Engine. For example, a server may have separate disks for the filesystem root, MySQL data, logs, and /tmp. Once you’ve created the Compute Engine disks and attached each one to the instance, how do you know which Compute Engine …

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Is there a “Primary Domain Controller” in Active Directory?

The Historical Answer With Windows NT, prior to the advent of Active Directory, there was one Primary Domain Controller (DC) per domain, and every other DC was a Backup. The Modern Answer When Active Directory was introduced with Windows 2000, domain controllers became fully multi-master. There is no primary domain controller. However, there are two …

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Monitoring with SNMP, Part 2: Command-line tools for active SNMP

In Part 1, I summarized the basic concepts of SNMP and defined the terms and acronyms used in this post. Now, I will show how to use SNMP to monitor actual devices. As an example, I will monitor an enterprise-grade uninterruptible power supply (UPS) and power distribution unit (PDUs) from Tripp-Lite. These devices have an …

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