R0106-HP MSR Router Series Interface Command Reference(V7)

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If the level detection is enabled on an asynchronous serial interface, the system detects the DSR signal
and the external cable. The interface is considered up only when the DSR signal is valid.
When determining whether a synchronous serial interface is up, the system detects by default the DSR
signal, DCD signal, and presence of a cable connection. The interface is considered up only when the
three signals are all valid.
If level detection is disabled on a synchronous serial interface, the system considers that the interface is
up after detecting the cable connection. The DTR and DSR are also reported up.
Examples
# Enable DCD on Serial 2/1/0.
<Sysname> system-view
[Sysname] interface serial 2/1/0
[Sysname-Serial2/1/0] detect dsr-dtr
# Enable DCD on Async 2/4/0.
<Sysname> system-view
[Sysname] interface async 2/4/0
[Sysname-Async2/4/0] detect dsr-dtr
Related commands
detect dcd
display interface async
Use display interface async to display information about an asynchronous interface.
Syntax
display interface [ async [ interface-number ] ] [ brief [ description | down ] ]
Views
Any view
Predefined user roles
network-admin
network-operator
Parameters
interface-number: Specifies an asynchronous interface by its number.
brief: Displays brief interface information. If you do not specify this keyword, the command displays
detailed interface information.
description: Displays complete interface descriptions. If you do not specify this keyword, the command
displays only the first 27 characters of interface descriptions.
down: Displays physically down interfaces and their down causes. If you do not specify this keyword, the
command displays information about interfaces in all states.
Usage guidelines
If you do not specify the async keyword, this command displays information about all interfaces on the
device.