June 15, 2026
CompTIA Network+ Study Guide: Passing the Exam on Your First Try
A practical Network+ study guide for 2026, covering exam domains, subnetting, study order, and the habits that help IT pros pass on the first attempt.
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June 1, 2026
CCNA in 2026: Is It Still Worth Pursuing?
A practical look at whether the Cisco CCNA certification still pays off in 2026 for network engineers, security pros, and federal IT teams alike.
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April 27, 2016
Learning More About Apple iOS9 MAC Address Randomization
Apple uses a variety of scans for wireless LAN/physical location information. There are Preferred Network Offload (PNO) Scans, Enhanced Preferred Network…
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November 17, 2014
Nothing Neutral About Net Neutrality
Colin's take on the net neutrality debate: what it means for ISPs, Internet content and users, and why the issue is anything but neutral.
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September 9, 2014
OSX Airport CLI Tool - Not Just for Airport APs
In this Post Colin explores the seldom mentioned OSX CLI airport utility and many of its WLAN configuration and and information gathering features.
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May 9, 2014
Offensive Wifi Gear Has Started to Arrive!
We are getting excited about our upcoming Offensive Wifi and Mitigation Techniques class. Gear has started to arrive!
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January 21, 2014
A Brief Explanation of IPv6 Address Types
A quick, clear explanation of the IPv6 address types: unicast, multicast and anycast, how they differ from IPv4, and why IPv6 has no broadcast.
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January 16, 2014
Am I Using IPv6?
Not sure if your connection uses IPv6 or IPv4? Quick, free websites and checks that show whether you are IPv6 capable on the Internet right now.
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January 15, 2014
Forcing ssh to use IPv6
How to force SSH to connect over IPv6 from a terminal, using IPv6 addresses, hostnames and the -6 flag, so you know which protocol your session uses.
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January 14, 2014
v6 Vertex #1: Viewing IPv6 Neighbors on Apple OS X
ITdojo's v6 Vertex - Quick Tips & Tricks for IPv6 Users - Using the command line to view neighbors on Apple OS X devices
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October 2, 2012
Pushing Firewall Admins into an ICMPv6 Frame of Mind
In this post Colin discusses issues the Path MTU discovery (PMTUD) and its implications on networking with IPv6.
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September 14, 2012
SSH Using Link-Local IPv6 Addresses
How to SSH to a remote host using a link-local IPv6 address (fe80::/10), and why you must specify the interface or zone ID to make it work.
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September 7, 2012
Deprecate, Deprecate, Deprecate
Those actively involved in the journey to IPv6 as the native transport encounter plenty of new terms and technology. One unexpected term stands out for Colin.
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September 6, 2012
Know Thy IPv6 Neighbor
In this post Colin reviews the items kept in the IPv6 neighbor cache and how to view the cache on Windows, Linux and Mac OSX systems.
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September 5, 2012
Resolver Cache - Linux vs Windows
How DNS resolver caching differs between Windows and Linux: why Windows caches lookups in the OS, why most Linux systems do not, and how to check.
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June 24, 2011
/64 or /126 Silliness
Should point-to-point links use /64 or /126 IPv6 prefixes? Why using /126 is IPv4 scar tissue and why address waste is not a real concern in IPv6.
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June 2, 2011
A Life Without Network Address Translation (NAT)
IPv6 means a world without NAT. In this post Colin attempts to help long-term IPv4 NAT users understand why everything is going to be just fine.
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May 9, 2011
On the Practical Feasibility of Ping Sweeping IPv6 Networks
Exploring the practical feasibility of ping sweeping IPv6 networks. Includes a spreadsheet for determining how long it will take to sweep your own network.
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May 4, 2011
Basic IPv6 Resolver Configuration in Ubuntu
Configuring Ubuntu's (any Linux distro, really) resolv.conf file with an IPv6 DNS server so you can natively query IPv6 DNS servers.
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May 2, 2011
Delivering DNS via IPv6 Router Advertisements
A brief introduction to the newly created RFC that allows routers to provide DNS server information via Router Advertisements (RA).
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April 28, 2011
IPv6 Addresses and UNC Path Names – Overcoming Illegal
The beloved UNC path name, familiar to all who administer Microsoft. After all these years there is something comfortable and familiar in the simple act of…
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April 28, 2011
Link-Local Addressing – So Much More Than FE80
IPv6 link-local addresses cover more than FE80. Why the FE80::/10 prefix also includes FE90, FEA0 and FEB0, with the binary math that explains it.
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April 28, 2011
What You dig and How You dig It
The Domain Internet Groper, or dig, as most of us know it, is considered by pretty much everybody in the 'nix community to be the replacement to nslookup.
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