CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer. For each port in the list, information about the process that opened the port is also displayed, including the process name, full path of the process, version information of the process (product name, file description, and so on), the time that the process was created, and the user that created it.

Kiwi CatTools is a freeware application that provides automated device configuration management on routers, switches and firewalls. Some of the many tasks Kiwi CatTools perform to make your life easier are: perform configuration backups and have any differences instantly e-mailed to you, issue commands via Telnet or SSH to many devices at once, change the configuration at scheduled times, change all your network device passwords in one go.

SoftPerfect Network Scanner is a free multi-threaded IP, NetBIOS and SNMP scanner with a modern interface and several advanced features. In addition, it allows you to mount shared resources as network drives, browse them using Windows Explorer, filter the results list and more. SoftPerfect Network Scanner can also check for a user-defined port and report if it is found open, resolve host names and auto-detect your local IP range.

IP Sniffer is a suite of IP Tools built around a packet sniffer.
The sniffer has basic features like filter, decode, replay, parse …