Loopback Detection - ADTRAN AOS Version R10.1.0 Command Reference Manual

Command Reference Guide EFM Group Command Set

loopback detection

Use the loopback detection command to enable loopback detection on the Ethernet in the first mile (EFM)
group. Use the no form of this command to disable loopback detection.
Syntax Description
No subcommands.
Default Values
By default, looback detection is enabled.
Command History
Release A5.02 Command was introduced.
Functional Notes
Loopback detection is a function of the EFM engine on the Quad single-pair high-speed digital subscriber
line (SHDSL) and Quad T1/E1 EFM network interface modules (NIM2s). When loopback detection is
enabled, the EFM engine attaches its media access control (MAC) address to EFM fragments when they
leave the module. The EFM engine also inspects EFM framents to verify that the MAC address on the
fragments does not match the EFM engine's own MAC address. If the EFM fragment does have the same
MAC address as the EFM engine, a loopback detection condition is asserted, and the EFM engine
automatically removes the offending link from the EFM group.
Usage Examples
The following example disables loopback detection
(config)#interface efm-group 1
(config-efm-group 1)#no loopback detection.
60000CRG0-35E Copyright © 2012 ADTRAN, Inc. 2168