ADC CUDA 3 - Manual (Page 346)

ADC Telecommunications, Inc.
344 C HAPTER 16: N ETWORK -L AYER B RIDGING
About Network-Layer Bridging
Network-layer bridging allows you to add the same IP address to multiple
physical interfaces throughout the system. Of particular value is the ability to
propagate the same IP gateway across cable interfaces on multiple DOCSIS
(CMTS) modules.
The cable modem, customer premise equipment (CPE), or Multimedia
Terminal Adapter (MTA) gateway determines the subnet to which a modem,
CPE, or MTA can belong. When the provisioning server receives a DHCP
request from a cable modem, CPE device, or MTA, it uses the cable modem,
CPE, or MTA gateway as a key to determine from which subnet or subnet
pool to assign an address.
Routing logic dictates that each interface in the system must have a unique
IP address. Network-layer bridging support allows you to group multiple
interfaces residing on multiple modules into a single logical interface, known
as a bridge group. After you assign an IP address to this bridge group, the
address will apply to all interfaces that are members of the bridge group.