Port Monitors (System Administration Guide, Volume 2)

System Administration Guide, Volume 2

Port Monitors

The main mechanism for gaining access to a service is through a port monitor. A port monitor is a program that continuously monitors for requests to log in or access printers or files.

When a port monitor detects a request, it sets whatever parameters are required to establish communication between the operating system and the device requesting service. Then the port monitor transfers control to other processes that provide the services needed.

The table below describes the two types of port monitors included in the Solaris environment.

Table 12-1 Port Monitor Types


Port Monitor	Description
listen(1M)	Controls access to network services, such as handling remote print requests prior to the Solaris 2.6 release. The default Solaris operating environment no longer uses this port monitor type.
ttymon(1M)	Provides access to the login services needed by modems and alphanumeric terminals. Admintool automatically sets up a `ttymon` port monitor to process login requests from these devices.

You might be familiar with an older port monitor called getty(1M). The new ttymon is more powerful; a single ttymon can replace multiple occurrences of getty. Otherwise, these two programs serve the same function.