Bay Networks 5390, Administering, Page: 748 / 888

C3-72 893-741-B
Using the CLI Commands
tap
The superuser tap command displays input and output on a device attached to a specific port. Any
input from the port performing the tap is inserted into the tapped port’s input stream. Table C3-31
describes the arguments for tap. The syntax is:
tap [–aksvx] port
Entering the tap command without the port argument displays the message CLI: Destination
address required; entering the tap port command without additional arguments displays any output
to the port on the terminal. Keystrokes from the terminal are interpreted as if they are typed on the
port. After establishing a tap, the terminal displays the message Warning: This port is being tapped,
unless the –s argument was selected. To stop a tap, break back to the CLI prompt and issue the CLI
kill for the tap job.
The tap command creates a Model 5390 job in the same way as the telnet and rlogin commands.
You can break back to the CLI prompt and execute other CLI commands. However, when tap is
not the active job, all activity on the tapped port is suspended.
Flow control on the tapping port affects the tapped port. Suspending output on the tapping port also
stops output on the tapped port.
The –k and –v arguments allow you to use tap as a limited software line monitor. You can monitor
traffic in both directions, including incoming special conditions (that is, line breaks, flow control,
and characters with special interpretations).
Payload Payload loopback is used to provide a loopback
toward the network. The data portion of the DS0s is
looped back.
Local Local loopback will loopback the data from the
customer side of both the T1 Network Interface and
the T1 Drop/Insert Interface.
NOTE:
Network direction loopbacks in most cases
can be initiated by the Telco. The front panel Test indi-
cator illuminates when the T1 is in loopback.
Table C3-30. Arguments for the T1_Loopback Command (continued)
Argument Description