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This is a series of posts designed to help readers understand how the Internet works. This specific post looks directly at how machines on different network segments communicate. In my previous post, we looked at how two machines on the same network segment exchange information by using frames. So what happens when two machines on different segments need to communicate? Encapsulation Before we get too involved in the discussion, we should take a peak at what an IP packet looks like. IP Packets relate to Ethernet frames much like one nesting doll relates to the rest in the set. ...

This is a series of posts designed to help readers understand how the Internet works. This specific post looks directly at how machines on the same network segment communicate with each other. We’ll look at the concept of a network segment in a future post, but for now all you need to think about is how two computers communicate on a Local Area Network. MAC Addresses Before we discuss how machines on the same LAN segment communicate, we need to understand what Media Access Control (MAC) addresses are. A MAC address is the physical address of a network adapter. These are 48 bit addresses that are expressed as 12 digit hexadecimal notation and are unique to each network adapter. Each manufacturer has an assigned range that they are to use for their first 24 bits, this is known as the Organizationally Unique Identifier (OUI). The second 24 bits are known as the Network Interface Controller (NIC) specific and must be unique within that vendor’s range. Keeping these ID’s unique is imperative for successful LAN communication. ...

HP announced a new virtual storage appliance (VSA) recently at their annual HP Discover conference. This is a virtual appliance based on the StoreOnce line (formerly known as D2D) of hardware appliances that HP has sold for a long time. These appliances have the catalyst software which allows for deduplication of all your backup data, hence the term StoreOnce. These devices have allowed administrators to switch from the older tape based backups to a virtual tape library (VTL) or a NAS type backup solution. It has replication options in it which allow for deduplicated data to be migrated or copied without re-hydrating the backups and wasting valuable bandwidth. It also allows for federated backups and when matched with HP Data Protector 8 (also newly released) can throttle bandwidth during backup operations in order to prevent production slow downs. ...

I’ve never paid too much attention to the different types of RAM (Random Access Memory) during my tenure as a Systems Engineer but wonder how much time it would have saved me in troubleshooting. This post is not only an attempt to educate other technicians, but an opportunity to refine my own knowledge of the subject. There are three main categories that I want to review. Ecc vs Non-ECC, Unbuffered vs Registered memory, and Memory Rank. ...

I recently purchased a Synology DS411slim NAS device for my home lab in order to quiet down my rack and start using up less power. Obviously to accomplish this I would need to fill it up with Solid State drives which have the added benefit of a large number of IOPS :) I screwed my four 480GB OCZ SSD’s into the drive cages and slipped them into the chassis. Really my only con for this device was getting the drives into the chassis. I did have to do a bit of wiggling to get them seated correctly. ...

This post was a direct result of a request from one of my readers. I hope that this post will explain VMware networks a bit more and how they fit into a production network. To begin I’d like to review how a VMware ESXi server might have its virtual switches and port groups setup to connect to a physical switch. Here is a list of networks that we’ll be working with. ...

I was recently interviewed by Andrew McCaskey from SDR News about the HP Discover conference. The interview is below http://www.youtube.com/watch?feature=player_detailpage&v=IUM-sDiHD18

A few months ago there was an annual vote to determine the top 50 virtualization bloggers according to vsphere-land.com. These top 50 bloggers are then added to the vLaunchPad where they will remain cataloged for a year until the next year’s voting. Kudos to Eric Siebert for running this whole process! TheITHollow.com was lucky enough to make the top 50 in it’s first year of existence and to celebrate I asked my good friends (well, family really) over at www.whateverinspires.com to create a top 50 badge to put on my site. They were happy to oblige and even created a top 25 and also a top 10. ...

Only a few years removed from when HP announced they were ditching the workstation part of their product line, they’ve announced a new set of desktops this week. The EliteOne 800 G1 The EliteOne 800 G1 is an all in one solution for companies that include the newer Intel 8 Series Q85 chipset which includes the Intel vPro technology. I haven’t been able to get my hands on playing with this yet, but essentially it uses the trusted execution environment in order to allow access to the PC even if it’s powered off, or if it has a virus. Perhaps this doesn’t seem like a big deal to end users, but the IT group that has to support these devices will certainly take notice. I liken it to having an iLO processor on every desktop so that troubleshooting can be done remotely by support. This will even allow off site or third party support to gain access in order to troubleshoot issues. ...

HP has a new MicroServer out that would be perfect for the anyone who is looking for a solid home lab server. The Microserver G7 was a fairly popular server for home computing enthusiasts and HP decided to add upon that line. The original reason for this server was for small businesses that wanted a small but stable server with features such as integrated Lights Out (iLO) but as it so happens, this line was pretty useful for those bloggers and certification junkies that wanted to take some HP Servers home with them. ...