Fping (open source) - fping is a program to send ICMP echo probes to network hosts, similar to ping, but much better performing when pinging multiple hosts.

PortsMonitor - PortsMonitor is a system utility for monitoring system TCP/IP network connections by application...

NetTK - NetTK, Network Tool Kit, is an Open Source alternative for monitoring and troubleshooting your...

Proc Net Monitor - SecurityXploded is an Infosec Research Organization offering 200+ FREE Security/Password Recovery Tools, latest Research Articles and FREE Training on Reversing/Malware Analysis

NetCrunch Tools - Our free network tools offer ping scanning, SNMP scanning, port and network service scanning, and more.

CurrPorts - CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer.