Charlie Schluting

Continuing our journey, it’s time to take a trip up the OSI Reference Model, and learn what this mysterious thing is all about. The network stack is of great significance, but not so much that it’s the first thing you should learn. We’ve waited to start the “layers” discussion for good reason: Many so-called networking […]

Welcome back! This edition of Networking 101 will give you the IP knowledge required to understand routing issues. Most everything on the Internet uses IP, and unlike Ethernet, knowing this protocol is pivotal to understanding how networking works with regards to the big picture. In upcoming articles, Networking 101 will explore TCP and UDP, routing […]

Virtualization allows you to better utilize your servers, and effectively increasing that utilization can be a big cost-saver. Now that it is so easy to duplicate server instances using virtual machines, it makes sense to start talking about the best way to take advantage of this new ability. Improved application availability and performance can now […]

Last week we explained how LDAP directories work, without really explaining how to use them. This week we’ll show how LDAP queries work, after explaining how the protocol works. The LDAP protocol supports just a few fairly easy to understand operations. Knowing what’s available provides administrators with the ability to surmise how various applications are […]

The most basic, yet important part of mastering Unix is to fully understand the nuances of file permissions. Tools exist to manage permissions easily, but true enlightenment and quick troubleshooting skills come to those who wholly master the concept. Remember, 80% of Unix problems are permissions issues. The Concept At the most basic level, there […]

When creating a disaster recovery plan, try not to only think about large-scale disasters. The more realistic disasters, perhaps a failure of an entire blade server, are much more likely to be relevant. In this article, we will talk about the concept of running servers without local disk space, and how SAN and server virtualization […]

Many moons have risen since we last gushed about Splunk, so what better way to reinvigorate our personal buzz than to install the latest version and write a how-to. After talking about a few neat features, we will briefly discuss how to set up central syslogging and how to install Splunk, before a tangent into […]

What exactly is the Internet? This article will explain the concepts required to understand BGP, our next Networking 101 topic. Shipping packets around the Internet requires the cooperation of separate organizations, so it isn’t as straightforward as learning about an IGP routing mechanism. Starting at the service provider level, let’s use an example of a […]

Storage networking is not unlike IP networking, most of the time. In the IP world there are numerous routing protocols and standards; you have dozens of options. In the storage world, however, there are no official routing protocols. Routing does exist, though it may not be what you’re imagining. Storage Area Networks can generally be […]

Connecting a host to your shiny new SAN is not the same as connecting a single disk, or even a direct-attached SCSI array. This article will explain the reasoning behind current best practices, and explain how to configure your storage for optimal reliability. Direct attached storage arrays, if you have used them, offer a great […]

The most critical, sometimes tedious, part of setting up a SAN is configuring each individual disk array. In this Storage Networking 101, we’ll delve into best practices and cover the general concepts you must know before configuring SAN-attached storage. There are three general steps when configuring a disk array: First, you create a RAID set. […]

This week’s look at building a homebrew NMS will focus on using SNMP to gather information about your network. Network Management requires SNMP, and you cannot escape the tangle of OID trees. Certain tools do make it easier, and once you learn a bit about them it becomes clear that this SNMP stuff is quite […]