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Rsync On CentOS 5.6

posted in General, Technical
by on September 9th, 2011 tags: , , , , ,

Just a quick blog about Rsync on A CentOS 5.6 box. I’m currently using Rsync to backup our Samba Server – all 500 Gigs of it!!

It’s going to take a few days but it will have an exact replica of the Samba server on the Rsync server and you don’t have to have any clients installed on other machines for Rsync to work. All you need is administrative credentials on the machine you are going to Rsync with.

Once I’ve figured all of this out, I will be setting my Rsync box to start backing up automatically every night (full backup) and also, when a file is changed on the Samba Server. I’m going to try and figure out the latter as I haven’t figured out how Rsync will be able to detect that a file has changed or been removed, etc. Once I have done so though I’m sure it’s going to be very handy, also I’ll be setting the Rsync box to backup all of the the user areas and profiles held on the DCs and also the users folder on the PCs.

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Encryption: Introduction and Applications

posted in General
by on September 1st, 2011 tags:

Encryption is the primary technical control used to enforce confidentiality of sensitive digital information. Extensively used in the enterprise environment, small and medium business users have recently seen an increased demand for cryptographic services. This post will examine some of the basics of encryptions as covered on the Cisco IINS 640-553 exam, and close with suggestions geared toward the small business contractor on how to implement email and file encryption.

Encryption algorithms are divided into two categories: symmetric and asymmetric. In symmetric encryption, the same key is used to encrypt and decrypt. Variable length keys are used to transform plain text according to the encryption algorithm. DES and its variations, AES, IDEA, the RC series, and Blowfish are all popular symmetric encryption algorithms. Symmetric encryption commonly uses three different techniques: Block, Stream, and Message Authentication Codes (MAC).

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VPN Options for Small Businesses

posted in General
by on August 22nd, 2011 tags:

Small businesses are an essential part of the network market. They provide economic growth and are crucial target for any networking company’s market share. Though small businesses do not generate as much revenue for networking companies as enterprise customers do, getting a business to adopt your products early on is sound marketing. As a business grows, the need for more flexible communication will prompt a small business owner to ditch their AT&T 2 Wire and move up to a better device.

The small business environment differs significantly from the enterprise. There is generally little or no existing infrastructure, a limited budget, and a particular need for user friendliness and simplicity for the end user. In this blog post, we will briefly review the basics of VPN protocols, how they apply to the small business environment, and then pay special attention to several specific solutions that are less known, particularly in the Mac world.

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Using TCPDUMP to Capture and Analyse Packets

posted in General, Technical
by on August 30th, 2009 tags: , , ,

Recently we needed to analyze packet flow through a router which had roughly 1000+ DSL customers running through. Initially we used Wireshark, but Wireshark has a nasty habit of crashing when trying to analyze so many packets and sessions. In fact this bug is a known bug and can be viewed here: http://wiki.wireshark.org/KnownBugs/OutOfMemory

Our capture server was initially running Windows 2003 with only 1GB of ram. This lasted roughly an hour or less capturing before dying. We upgraded the ram to 4GB but the server would still crash, albeit after about 2 hours now.

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Beginners Guide to IPv6

posted in General, Technical
by on July 12th, 2009 tags: ,

Welcome to IPv6. This is a very beginner guide into how IPv6 addressing works. You may already be aware of the size difference of IPv6 (128 bits) compared to IPv4 (32 bits), which gives us a virtually unlimited amount of addresses. To give a perspective, you could allocate more than the entire IPv4 address space to every human on the planet and still have plenty of addresses leftover. There are approximately 665,570,793,348,866,943,898,599 IPv6 address for every square meter of the surface of the Earth.IPv6 addressing is a little different than IPv4.I won’t go in depth with explanation; this is simply just to get you a basic grasp of the IPv6 concept so that you won’t be completely lost when you see one.

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