Cisco cBR Series Configuration Guide

scope S10.1.1.0 set policy=cmts-cisco
scope S10.1.1.0 set selection-tags=tag-CM
scope S10.1.1.0 set primary-scope=S24.1.1.0
client 01:02:03:04:05:06 create client-class-name=class-PC
client ab:cd:ef:01:02:03 create client-class-name=class-CM
client default create action=exclude
dhcp enable client-class
dhcp enable one-lease-per-client
save
dhcp reload
In addition to the DHCP server setup, you might want to enable packet-tracing. When packet-tracing is enabled,
the server parses both requests and replies, and then adds them to the logs. If you do enable tracing, performance
will be adversely affected, and the logs will roll over quickly.
Use the following nrcmd command to set packet tracing.
DHCP set log-settings=incoming-packet-detail,outgoing-packet-detail
Cable Modem DHCP Response Fields
Each cable interface on the broadband network requires the following fields in the DHCP response:
• CM’s IP address
• CM’s subnet mask
For cable operators with less experience in networking, you can fill in a guess based on the network number
and indicate how your IP network is divided.
Note
•
Name of the DOCSIS configuration file on the TFTP server intended for the cable interface
•
Time offset of the cable interface from the Universal Coordinated Time (UTC), which the cable interface
uses to calculate the local time when time-stamping error logs
•
Time server address from which the cable interface obtains the current time
DOCSIS DHCP Fields
DOCSIS DHCP option requirements include:
•
IP address of the next server to use in the TFTP bootstrap process; this is returned in the siaddr field
•
DOCSIS configuration file that the cable interface downloads from the TFTP server
If the DHCP server is on a different network that uses a relay agent, then the relay agent must set the
gateway address field of the DHCP response.
Note
•
IP address of the security server should be set if security is required
Cisco cBR Series Converged Broadband Routers Application—Voice and Video Configuration Guide
45
Cisco Network Registrar for the Cisco CMTS Routers
Cable Modem DHCP Response Fields

Cisco cBR Series Specifications

General

Category	Network Router
Modular Design	Yes
Operating System	Cisco IOS XE
Model Examples	cBR-8, cBR-4
Product Series	cBR Series
Purpose	Converged Broadband Router
DOCSIS Support	DOCSIS 3.1
Redundancy	Yes
Management	Cisco Prime
Product Family	cBR Series
Downstream Frequency Range	Up to 1.2 GHz
Upstream Frequency Range	Up to 204 MHz
Modulation Schemes	QAM
Power Supply	Redundant AC or DC power supplies
Operating Temperature	0°C to 40°C
Storage Temperature	-40°C to 70°C
Humidity	5 to 95% noncondensing