Checklist for Using Loopback Testing for SONET Interfaces

Purpose

To use loopback testing to isolate SONET interface problems.

Action

Table 28 provides the links and commands for using loopback testing for SONET interfaces.

Table 28: Checklist for Using Loopback Testing for SONET Interfaces

Tasks

Command or Action

Diagnose a Suspected Hardware Problem with a SONET Interface
  1. Create a Loopback
 

Connect the transmit port to the receive port.

[edit interfaces interface-name sonet-options]
set loopback local
show
commit

  1. Set Clocking to Internal

[edit interfaces interface-name]
set clocking internal
show
commit

  1. Verify That the SONET Interface Is Up

show interfaces so-fpc/pic/port

  1. Clear SONET Interface Statistics

clear interfaces statistics so-fpc/pic/port

  1. Check That the Received and Transmitted Path Trace Are the Same

show interfaces so-fpc/pic/port extensive

  1. Force the Link Layer to Stay Up
 

[edit interfaces interface-name]
set encapsulation cisco-hdlc
show
commit

[edit interfaces interface-name]
set no-keepalives
show
commit

  1. Verify the Status of the Logical Interface

show interfaces so-fpc/pic/port show interfaces so-fpc/pic/port terse

  1. Ping the SONET Interface

ping interface so-fpc/pic/port local-IP-address bypass-routing count 1000 rapid

  1. Check for SONET Interface Error Statistics

show interfaces so-fpc/pic/port extensive

Diagnose a Suspected Circuit Problem
  1. Create a Loop from the Router to the Network

[edit interfaces interface-name sonet-options]
set loopback remote
show
commit

  1. Create a Loop to the Router from Various Points in the Network

Perform Steps 2 through 8 from Diagnose a Suspected Hardware Problem with a SONET Interface.

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