Lab 6. Verifying Cisco HDLC Encapsulation
CCNA 200–301
Lab Objective:
The objective of this lab exercise is to verify Cisco HDLC encapsulation, which is the default encapsulation method for WAN interfaces on Cisco IOS routers.
Lab Purpose:
Cisco HDLC verification is a fundamental skill. Cisco HDLC encapsulation is the default encapsulation on all Cisco router Serial interfaces. As a Cisco engineer, as well as in the Cisco CCNA exam, you will be expected to know how to verify Cisco HDLC encapsulation.
Simulator:
Cisco Packet Tracer
Lab Topology:
Please use the following topology to complete this lab exercise:
Task 1:
Configure hostnames on R1 and R2 as illustrated in the topology.
Task 2:
Enable Serial interfaces on R1 and R2. The Serial0/0 interface on R2 is identified as the DCE in the topology. Configure the DCE interface on R2 to provide clocking to R1. The clock speed should be 250 Kbps. Remember that 1 Kbps = 1000 bps. Verify that R2 is sending clocking information and that R1 receives this information from R2.
Task 3:
Configure IP addressing on R1 and R2 Serial0/1/0 interfaces as illustrated in the topology. Verify your interface encapsulation, which should be HDLC by default.
Task 4:
Enable debugging on the Cisco router to validate that HDLC keepalive messages are being sent between the two routers. Ensure that you disable debugging when you are finished. Verify that HDLC messages are sent in the keepalive interval that is listed under the interface, which should be approximately every 10 seconds.
Task 1:
For reference information on configuring hostnames, please refer to earlier labs.
Task 2:
R1(config)#interface serial0/1/0
R1(config-if)#no shut
R1(config-if)#end
R2(config)#interface serial0/1/0
R2(config-if)#no shut
R2(config-if)#end
R2#show controllers serial0/1/0
NOTE: The show controllers command will tell you whether the interface is the DCE side (which provides the clocking) or the DTE side (which receives the clocking) on a particular router interface.
R2#conf t
R2(config)#interface serial0/1/0
R2(config-if)#clock rate 250000
R2(config-if)#end
R2#show controllers serial0/1/0
R1#show controllers serial0/1/0
Task 3:
For reference information on configuring IP addressing, please refer to earlier labs.
R1#show interfaces serial0/1/0
R2#show interfaces serial0/1/0
Task 4:
R1#debug serial interface
*Mar 1 01:17:34.686: Serial0/0: HDLC myseq 232, mineseen 232*, yourseen 230, line up
*Mar 1 01:17:44.686: Serial0/0: HDLC myseq 233, mineseen 233*, yourseen 231, line up
*Mar 1 01:17:54.687: Serial0/0: HDLC myseq 234, mineseen 234*, yourseen 232, line up
R1#undebug all
