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.
CurrPorts - CurrPorts displays the list of all currently opened TCP/IP and UDP ports on your local computer.
Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
TCPView - TCPView is a Windows program that will show you detailed listings of all TCP and UDP endpoints on...
NetCrunch Tools - Our free network tools offer ping scanning, SNMP scanning, port and network service scanning, and more.
TcpView For Linux - TcpView For Linux. Touch screen friendly design graphical network connections viewer for Linux.