Serial Port Redirector
Serial Port Redirector is used to connect a serial application to a remote TCP socket. This allows you to utilize modern hardware COM servers without changing your software or exchange data between a TCP/IP application and an old-fashioned program that can only connect to a serial port. ... They are plugged into USB or network adapters and can only send/receive data via TCP/IP networks. ... With Serial Port Redirector, you can easily control remote hardware COM servers via a TCP/IP network from your serial application designed to work with locally connected devices only.
http://www.serial-port-redirector.com/serial-port-redirector.zip - 772Kb - Download - Screenshot

PortsLock
PortsLock is a firewall with user-level access controls for Windows NT/2000/XP. Once PortsLock is installed, administrators can assign permissions to TCP/IP connections, just as they would in managing permissions on an NTFS partition of a hard disk. It lets you control which users can access... You can also set allowed/denied TCP/UDP ports and IP addresses for incoming and outgoing connections. ... PortsLock enhances access control possibilities for system administrators, helps them to build a more secure network environment, and protects corporate networks against attacks from the inside.
http://www.protect-me.com/portslock.zip - 2Mb - Download - Screenshot

Network+ practice tests from SimulationExams.com
About CompTIA(r) Network+ Certification: Exam topics include Knowledge of Networking Technologies, Layers, TCP/IP, Knowledge of Networking Practices, Installing, Supporting and Troubleshooting Networks including Ehternet 10baseT, 100BaseT, Token Ring networks. ... Test mode is timed and the candidate is expected to complete the test within specified time. ... The review mode allows a candidate to quickly review the correct questions, and answers. ... At the end of the test, one can analyze the wrongly answered questions against the correct questions.
http://www.simulationexams.com/downloads/comptia/se_net.zip - 3Mb - Download - Screenshot

Net Profile Switch
JitBit Net Profile Switch allows connecting a computer to two or more networks.. Ideal for laptop/notebook users, who travel from one network location to another. It switches a computer between multiple network configurations (profiles) with one click of a button. ... If you deal with two or more locations, you can benefit from this net switcher utility which creates a profile with your configuration settings: TCP/IP-settings, browser-proxy (Firefox-compatible, Opera-compatible), network drives, default printer settings, SMTP server address etc.
http://www.jitbit.com/files/NetProfileSwitchSetup.zip - 1Mb - Download - Screenshot

Etherscan Analyzer
Etherscan Analyzer is an advanced network sniffer and protocol analyzer for Windows. With Etherscan, you can capture and analyze all packets over the local network. Etherscan decodes all major protocols, including Ethernet, NetBEUI, TCP/IP, and others. ... Etherscan Analyzer is capable of reconstructing TCP/IP sessions. ... Also you can set aliases to IP or MAC addresses. ... Using these flexible, powerful filters during or after capture you can isolate traffic by specific node, protocol, error type and/or packet content.
http://www.etherscan.com/esa.exe - 1Mb - Download - Screenshot

Network Traffic Monitor
Network Traffic Monitor shows you which processes in your machine are causing how much TCP/IP network traffic and over which IP ports this traffic takes place. For each process it can show detailed information, including the path to the process executable, the remote IP address, and the... An animated system tray icon will show you when IP traffic is taking place. ... Network Traffic Monitor can give you a historic overview of the network traffic and can save that info to an Excel spreadsheet or a text file for later examination.
http://www.nicocuppen.com/nt.exe - 618Kb - Download - Screenshot

IP Shifter
IP Shifter is a smart software tool that helps you to change your TCP/IP related settings easily and quickly. If you work dynamically at several locations in the network (due to business), you need to be connected in different offices, or you need to use your computer in more than one network,... IP address, Subnet mask, Gateway, DNS) frequently, so IP Shifter is a product for you! ... You do not need to reboot your PC every time after applying of the selected configuration. ... your new configuration will be active in the system instantly.
http://www.zqware.com/download/IPShifterSetup.exe - 855Kb - Download - Screenshot

Network Serial Port Kit
Network Serial Port Kit allows you to connect any serial port devices over the TCP/IP network or Internet. Creation of local virtual serial ports pairs are available as well. Program creates up to 254 virtual serial ports at a time. Physical COM ports located on remote computer can be connected... For example you can convert usual PC to "Serial Port Server" so then you can connect any serial device directly to a TCP/IP network and communicate with that device from any other PC in the same network or across the Internet.
http://www.network-serial-port.com/network-serial-port-kit.zip - 980Kb - Download - Screenshot

iSpeed for Windows
The settings for TCP/IP connections established when installing Windows do not typically give you the optimal throughput for your TCP/IP network connections. The simple changes that are facilitated by using iSpeed can easily increase your throughput by 60% or more! ... Faster web browsing, faster downloads, quicker action for those internet multiplayer games! ... What does that mean?
http://www.hms.com/apps/issetup3.exe - 3Mb - Download - Screenshot

AlarIT Virtual Serial Driver .IP (AVSD.IP)
While the operation of different facilities, which are connected to a computer via serial port, there may appear the necessity to start up utility program (for these facilities) not in the machine, to which the facilities connect directly, but in the remote machine, that is connected to the... IP server is a service which realizes the exchange between a real driver of the serial port and TCP/IP. ... IP client is the service, which realizes the exchange between AVSD and TCP/IP. ... The use of our product gives you the possibility to give the remote access to serial port via TCP/IP.
http://www.alarit.com/downloads/products/avsdnet.zip - 576Kb - Download - Screenshot