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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter2 Configuring the Cable Modem Termination System for the First Time
Reviewing Your Settings and Configurations
When Baseline Privacy is enabled, the CiscouBR10012router routes encrypted and decrypted packets
from a host or peer to another host or peer. BPI is configured with key encryption keys (KEKs) and traffic
encryption keys (TEKs). A KEK is assigned to a CM, based on the CM’s service identifier (SID), and
permits the CM to connect to the CiscouBR10012router when Baseline Privacy is activated. The TEK
is assigned to a CM when its KEK has been established. The TEK is used to encrypt data traffic between
the CM and the CiscouBR10012router.
KEKS and TEKs can be set for Baseline Privacy on the HFC network to expire based on a grace-time
or a life-time value, defined in seconds. A grace-time value assigns a temporary key to a CM to access
the network. A life-time value assigns a more permanent key to a CM. Each CM that has a life-time
value assigned requests a new lifetime key from the CiscouBR10012router before the current one
expires.
To set the duration in seconds for KEK or TEK grace-time or life-time, use the following commands
in global configuration mode. To restore the default values, use the no form of each command.
cable privacy kek {grace-time [seconds] | life-time [seconds]}
no cable privacy kek {grace-time | life-time}
cable privacy tek {grace-time [seconds] | life-time [seconds]}
no cable privacy tek {grace-time | life-time}
Syntax Description
Tip Use the show cable modem command to identify a CM with encryption and decryption enabled. The
online(pk) output of this command reveals a CM that is registered with BPI enabled and a KEK
assigned. The online(pt) output reveals a CM that is registered with BPI enabled and a TEK assigned.
Should you want to change the CiscouBR10000series default of 56-bit encryption and decryption to
40-bit, use the “40 bit DES” option:
Router(config-if)# cable privacy ?
40-bit-des select 40 bit DES
^^^^^^^^^^
authenticate-modem turn on BPI modem authentication
authorize-multicast turn on BPI multicast authorization
kek KEK Key Parms
mandatory force privacy be mandatory
tek TEK Key Parms
Software then generates a 40-bit DES key, where the DES key that is generated and returned masks the
first 16 bits of the 56-bit key to zero in software. To return to 56-bit encryption and decryption after
changing to 40-bit, enter the no command in front of the “40 bit des” option.
grace-time seconds (Optional) Length of key encryption grace-time in seconds. Valid range is
300 to 1800 seconds. The default grace-time value is 600 seconds.
life-time seconds (Optional) Length of the key encryption life-time in seconds.Valid range is
86,400 to 604,8000. The default life-time value is 604800 seconds.