Chapter 15: Interface IP Configuration
STANDARD Revision 1.0 C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved. 432
Primary Operation — When the DHCP Relay Agent is defined for Primary operation on a specific CAM subinterface, the
Primary IP address of the interface is used to populate the gi_addr field of all DHCP messages originating from either CMs
or Hosts (CPEs).
Policy Operation — When the DHCP Relay Agent is defined for Policy operation on a specific CAM subinterface, the
Primary IP address of the interface is used to populate the gi_addr field with all DHCP messages originating from CMs. For
Hosts (CPEs), a designated secondary IP address of the interface is used. If multiple secondary IP addresses are defined for
dhcp-giaddr support, then the DHCP Relay Agent uses round-robin selection based on device class, choosing the next entry
in the list with each new DHCP transaction.
Device Classes for DHCP-GIADDR
Device classes may be configured for the DHCP GIADDR:
For example:
configure interface cable-mac 1 ip address 10.10.10.1 255.255.255.0 secondary dhcp-giaddr ?
cpe...Regular CPE device secondary DHCP giaddr
mta MTA device secondary DHCP giaddr
ps....CableHome PS device secondary DHCP giaddr
stb DSG STB device secondary DHCP giaddr
Where: CPE = Customer Premise Equipment
MTA = Multimedia Terminal Adapter (PacketCable)
PS = Portal Server (CableHome)
STB = Set-top Box (sometimes called DOCSIS Set-top Gateway, or DSG.
Device Classes for the Helper Address
Device classes may be configured for the DHCP helper address. For example:
configure interface cable-mac 1 ip helper-address 10.10.10.1 ?
cable-modem Cable modem traffic
host All CPE host types traffic
cpe Regular CPE device secondary DHCP giaddr
mta MTA device secondary DHCP giaddr
ps CableHome PS device secondary DHCP giaddr