Checklist for Using Loopback Testing for Multichannel DS3 Interfaces

1. Create a Loopback

• 1. Create a Physical Loopback

Connect the TX port to the RX port.

• 2. Configure a Local Loopback

[edit interfaces interface name (t3-options | t1-options)]
set loopback local
show
commit

2. Verify That the Interface Is Up

show interfaces (ds-fpc/pic/port:channel:channel | t1-fpc/pic/port:channel)

3. Clear Interface Statistics

clear interfaces statistics (t1-fpc/pic/port:channel | ds-fpc/pic/port:channel:channel)

4. Force the Link Layer to Stay Up

• 1. Configure Encapsulation to Cisco-HDLC

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

• 2. Configure No-Keepalives

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

5. Verify the Status of the Logical Interface

show interfaces (ds- fpc/pic/port:channel:channel | t1-fpc/pic/port:channel)

6. Ping the Channelized Interface

ping interface (ds-fpc/pic/port:channel:channel | t1-fpc/pic/port:channel) local-IP-address bypass-routing count 1000 rapid

7. Check for Interface Error Statistics

show interfaces (ds-fpc/pic/port:channel:channel | t1-fpc/pic/port:channel) extensive

1. Create a Loop from the Router to the Network

• 1. Loop the Entire T3 Interface towards the Network

[edit interfaces interface-name t3-options]
set loopback remote
show
commit

• 2. Loop a Particular T1 Channel towards the Network

[edit interfaces interface-name t1-options]
set loopback remote
show
commit

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

Perform Steps 2 through 8 from .