28.06.2014 Views

Discussion

Discussion

Discussion

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Run the loopback test, which sends 1,000 ping messages rapidly and reports the<br />

results in a single message:<br />

aviva@RouterF> ping interface t1-0/0/3 10.0.13.2 bypass-routing count 1000 rapid<br />

PING 10.0.13.2 (10.0.13.2): 56 data bytes<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<br />

--- 10.0.13.2 ping statistics ---<br />

1000 packets transmitted, 1000 packets received, 0% packet loss<br />

round-trip min/avg/max/stddev = 2.376/19.102/369.920/35.795 ms<br />

<strong>Discussion</strong><br />

To perform a loopback test on the T1 interface, first configure the T1 interface to use<br />

local loopback mode. Also include the encapsulation cisco-hdlc and no-keepalives<br />

statements to force the interface to stay up so you can run the ping loopback test.<br />

Then you need to create a physical loopback at the T1 port by connecting a T1 loopback<br />

plug to the T1 port. You can make a T1 loopback plug by connecting pin 1 to<br />

pin 4 and pin 2 to pin 5 on an RJ-48 plug.<br />

The first commands in this recipe configure the loopback. After making sure the<br />

interface is up and zeroing all interfaces statistics, run the loopback test, which sends<br />

1000 ping messages rapidly and reports the results in a single message. Include the<br />

bypass-routing option in the ping command to directly ping a system on an attached<br />

network, bypassing normal routing tables. This option forces the packets to be transmitted<br />

out the interface, because they have a local destination address and from an<br />

IP point of view, they are already at their destination.<br />

If there are any problems on the link, you see input and output errors in the show<br />

interfaces extensive command output. This output also shows that 1,000 ping<br />

messages were sent (in Output packets) and 1,000 responses were received (in Input<br />

packets).<br />

aviva@RouterF> show interfaces t1-0/0/3 extensive<br />

Physical interface: t1-0/0/3, Enabled, Physical link is Up<br />

Interface index: 140, SNMP ifIndex: 38, Generation: 21<br />

Description: J2300 T1 line in local office<br />

Performing a Loopback Test on a T1 Interface | 227<br />

This is the Title of the Book, eMatter Edition<br />

Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!