System Administration Guide: Advanced Administration

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

Table 10–1 Port Monitor Types

Port Monitor 

Man Page 

Description 

listen

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

ttymon(1M)

Provides access to the login services needed by modems and alphanumeric terminals. Serial Ports Tool 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.