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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter4 Managing Cable Modems on the Hybrid Fiber-Coaxial Network
Activating CM Authentication
Activating CM Authentication
The CiscouBR10000series CMTS can be configured to require all CMs to return a known text string
to register with the CMTS and gain access to the network. The text string can be from 1 to 80 characters
in length. The default setting is "on" (CM authentication is activated).
To activate CM authentication, use the following command in cable interface configuration mode:
Tip Be sure that you enter the correct slot and port number in cable interface configuration mode. Verify
that the CM is using baseline privacy interface (BPI) and that it is assigned to a quality of service
(QoS) with privacy active. Verify that the cable interface configuration file contains a matching key.

Verifying CM Authentication

To verify if CM authentication has been activated or deactivated, enter the command
more system:running-config and look for the cable interface configuration information. If CM
authentication has been activated, it does not appear in this output. If CM authentication has been
deactivated, it appears in this output asno cable secret-shared,” as shown in this command output
excerpt:
Router# more system:running-config
Building configuration...
Current configuration:
!
interface Cable5/0/0
ip address 1.1.1.1 255.255.255.0
no keepalive
no cable secret-shared
cable insertion-interval 150000
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
cable upstream 0 fec
cable upstream 0 scrambler
no cable upstream 0 shutdown
!

Troubleshooting CM Authentication

If you are having trouble, make sure that you entered the correct slot and port numbers when you entered
cable interface configuration mode. For additional troubleshooting information, refer to Chapter6,
Troubleshooting the System.”
Command Purpose
cable shared-secret [0|7] authorization-key
no cable shared-secret
Enables CM authentication:
0 specifies an unencrypted authentication key.
7 specifies an encrypted authentication key.
Disables CM authentication.