The oldest and simplest form of network management is the remote login. In fact, most fancy routers support TELNET access to some sort of command prompt. Many operations can be performed in no other way.
However, more sophisticated network management tools have been developed, for a variety of reasons. Remote logins are designed for human interaction, and use command style and syntax that varies between different hardware and software platforms. A more specialized and standardized approach allows automated software tools to easily perform management operations on a variety of platforms. Also useful is a standard method of reporting network failures and error conditions to a centralized location.
For Internet engineers, the SNMP Protocol is currently the most popular vehicle for network management.