4000 Router Series Interface Command Reference

153

Examples

# Configure E3 2/0 interface to operate in the FE3 mode, setting the DSU mode to 1 and the subrate to

3000 kbps.

<Sysname> system-view

[Sysname] controller e3 2/0

[Sysname-E3 2/0] using e3

[Sysname-E3 2/0] fe3 dsu-mode 1

[Sysname-E3 2/0] fe3 subrate 3000

loopback

Use loopback to configure the loopback mode of the CE3 interface.

Use undo loopback to restore the default.

Syntax

loopback { local | payload | remote }

undo loopback

Default

Loopback is disabled on the CE3 interface.

Views

CE3 interface view

Predefined user roles

network-admin

Parameters

local: Enables internal loopback on the CE3 interface.

payload: Enables external payload loopback on the CE3 interface.

remote: Enables external loopback on the CE3 interface.

Usage guidelines

Loopback is intended for test use. Disable loopback in other cases.

If a CE3 interface encapsulated with PPP is placed in a loopback, the state of the link layer protocol is

reported as down.

Examples

# Enable internal loopback on interface E3 2/0.

<Sysname> system-view

[Sysname] controller e3 2/0

[Sysname-E3 2/0] loopback local

national-bit

Use national-bit to configure the national bit on the CE3 interface.

Use undo national-bit to restore the default.