NetCrunch Tools is a completely free toolkit for network professionals, featuring Ping, Traceroute, Wake OnLAN, DNS Info, Who Is, Ping Scanner, Service Scanner, Open TCP Port Scanner, SNMP Scanner, DNS Audit and Mac Resolver in one.
It can work standalone, or in conjunction with the NetCrunch network monitoring system, an all-in-one, agentless network monitoring and management suite.
It is completely free to use, with no usage limitations of any kind. Future updates can be installed from the NetCrunch Tools homepage, or through the software itself.