A Network Management System (NMS) developed by the Merit NOC (www.merit.edu), Rover (more properly, Internet Rover) uses two daemons to run specific tests on a given list of network nodes. The first daemon is pingd. This provides a single test - a simple ICMP Echo (more generally known as a "ping", hence the name) to the target nodes. The second, more complex, daemon is called InetRoverd. This daemon will test any given TCP port (with specific, named tests for telnet, smtp, named, and gopher), as well as running a disk usage check against servers listed in the hostfile, and checking to see if a given file exists on those servers. If any of the tests fail, Rover will throw an alert notice onto its display (which runs in a simple vt100 terminal) and make an entry in its logfile. The list of nodes is given in a plaintext file, with each node having a line which documents its IP address, a short description of the node, and what test (or tests) should be run against that node.

Given the simplicity of configuration combined with its ability to run in text-only environments, it isn't surprising that Rover is so popular. When one combines these benefits with the fact that it is freely available, it is nearly the perfect NMS. The only major drawbacks are the lack of SNMP polling ability, and the fact that each hostfile has a maximum size of 2000 entries. The reason for this is that the daemons continually iterate over the hostfile, and anything over 2000 entries would cause an unacceptable delay in reporting problems on the network.