Checklist for Using Loopback Testing for ATM Interfaces

1. Create a Loopback

• 1. Create a Physical Loopback

Connect the transmit port to the receive port.

• 2. Configure a Local Loopback

[edit interfaces interface-name (sonet-options | t3-options)]
set loopback local
show
commit

2. Set Clocking to Internal

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

3. Verify That the ATM Interface Is Up

show interfaces at-fpc/port/pic

4. Clear ATM Interface Statistics

clear interfaces statistics at-fpc/port/pic

5. Ping the ATM Interface

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

6. Check for ATM Interface Error Statistics

show interfaces at-fpc/port/pic extensive

1. Create a Loop from the Router to the Network

[edit interfaces interface-name (sonet-options | t3-options)]
set loopback remote
show
commit

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

Perform Steps 2 through 6 from Diagnose a Suspected Hardware Problem with an ATM1 or ATM2 IQ Interface.