Ad Blocking Hosts File - http://www.mvps.org/winhelp2002/hosts.htm If you are tired of some of those stupid banners and annoying flashing kick the monkey ads, this is for you. This Ad Blocking Hosts file is a very simple hack that you can apply to your PC to keep Internet Explorer from loading these ads. It also keeps parasites away. Well actually it keeps your computer from contacting the servers that send you their ads.
A Plan For Spam - http://www.paulgraham.com/spam.html This article describes the spam-filtering techniques used in some spamproof web-based mail readers. It covers an improved algorithm described as Better Bayesian Filtering.
DNS for Rocket Scientists - http://www.zytrax.com/books/dns/ This Open Source Guide is about DNS and (mostly) BIND 9.x on Linux (Fedora Core), BSD's (FreeBSD, OpenBSD and NetBSD) and Windows (Windows 7 and 10). It is meant for newbies, Rocket Scientist wannabees and anyone in between.
Free CCNA Study Guide - http://www.freeccnastudyguide.com/ Offers three free CCNA study guides as well as lab kits for practice at home.
Free CCNA Workbook - https://www.jann.cc/2013/02/02/linux_watchdog.html Exactly as it says, a CCNA workbook for lab practice with a focus on GNS3.
Dig web interface - http://digwebinterface.com/ An online version of the dig DNS query tool.
Gibson Ressearch Corporation - http://www.grc.com/ Steve Gibson's and Gibson Research Corporation's Web homepage has many usefull tools and articles. Test your network security with their shields-up or read up on how to protect yourself online.
HTTP Status Messages - http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html HTTP Status Messages are errors that web servers and web browsers generate. There are several types that you can read about here. Sometimes get one of these trying to get to a web site - explains the different http codes.
IEEE OUI and Company_id Assignments - http://standards.ieee.org/regauth/oui/index.shtml Allows you to find out the manufacturer of a nic if you know the mac address.
InterNIC - http://www.internic.net/ This website has been established to provide the public information regarding Internet domain name registration services and will be updated frequently.
IPv6 MTU Gotchas and other ICMP issues - http://blogs.cisco.com/enterprise/ipv6-mtu-gotchas-and-other-icmp-issues From a home network, you can successfully ping or traceroute to some IPv6 hosts, but cannot subsequently open a web page or use other applications with it. How can this be? Maximum Transmission Unit (MTU) gotchas explained.
JTA - Telnet/SSH/Terminal - http://javassh.org/ It is a Telnet and SSH terminal...that is JAVA based.
Looking Glass - https://www.us.ntt.net/support/looking-glass/ With Looking Glass you can ping, traceroute and get bgp details from switches located across the world.
MacInTouch Spam and Scam Resources - http://www.macintouch.com/spam.shtml Spam is annoying. Face it, if you aren't prepared to deal with it, you are in for one horrible email box. This page covers preventing spam, reporting and responding to spam as well as news and reports.
NetCraft - http://www.netcraft.com/ Netcraft has some unique tools for showing what a server runs and how long it has been running along with other trend information. You can also see siten on the move, internet exploration, internet data mining, performance, security, uptime and other tidbits.
NetStumbler - http://www.netstumbler.com/ Net Stumbler is the home of the award-winning wireless networking tool and the best source for your daily Wi-Fi, WiMAX, 3G and VoIP news.
Security Tango - http://securitytango.com The Security Tango is my name for the dance you have to do every time you want to assure yourself that your computer is free of viruses, spyware, keystroke loggers, backdoors, trojans, and other forms of malware (click the Definitions button on the left to see what all those things mean). It's something you need to do regularly and often - daily is not too often! The simple act of getting on the Internet and downloading email or going to a Web page can expose your computer to malicious crackers who would love to take over your machine for their own use.
TCP/IP Ports - http://www.chebucto.ns.ca/~rakerman/port-table.html This page describes TCP Port numbers in great detail.
Traceroute - http://www.traceroute.org/ At this site you can perform traceroutes to your heart's content.
Trunks vs LACP? What is the difference? - https://community.spiceworks.com/topic/477934-hp-procurve-trunk-or-lacp-between-two-switches This suggest that LACP just tosses the links together, whereas TRUNKS allows multiple vlan’s.
UltraVNC - http://www.uvnc.com/index.html UltraVNC is a powerful, easy to use and free software that can display the screen of another computer (via internet or network) on your own screen. The program allows you to use your mouse and keyboard to control the other PC remotely. It means that you can work on a remote computer, as if you were sitting in front of it, right from your current location. If you provide computer support, you can quickly access your customer's computers from anywhere in the world and resolve helpdesk issues remotely! With addons like SingleClick your customers don't even have to pre-install software or execute complex procedures to get remote helpdesk support.
VNC (RealVNC) - http://www.realvnc.com/ VNC stands for Virtual Network Computing. It is a multiplatform program that allows you to remotely connect to servers and workstations. It works on Mac, Linux and Wendows. It is completely free and very easy to configure and setup.
WebReference.com - http://webreference.com/ A webmaster's delight of webmaster's information and all things webish
Wire Shark - http://www.wireshark.org/ Network analyzer and packet sniffer.
ZPhone Project - http://zfoneproject.com/ You CAN secure VoIP communications for free. Though in beta, this is a very promising technology to secure any VoIP conversation.