7-18 Riverstone Networks RS Switch Router User Guide Release 8.0
CMTS Configuration Examples CMTS Configuration Guide
7.7.3 Example Three: Overlapping VLANs with Multiple DHCP Servers andClient-VLAN Bindings
The advantage of the client-VLAN bindings configuration is that clients and modems can be on different VLANs. This
provides the added flexibility of using modems and Client Premise Equipment (CPEs) in different subnets.
Client-VLAN bindings can be configured either from the CLI or through vendor extensions. See TFTP Configuration
Files for information about vendor extensions.
Following, is the configuration:

TFTP Configuration Files

Client-VLAN bindings can be specified in the modem's TFTP configuration file rather than from the CLI. This file is
configured manually through a configuration editor or by provisioning server software. Although TFTP configuration
files are part of the DOCSIS standard, some modems may not be capable of recognizing vendor extensions. A vendor
extension is the line in the file that identifies a vendor. See the first line in the file below.
! Configure the RS
cmts set headend cm.5.1 auth-str DOCSIS
cmts set uschannel cm.5.1 upstream 1 state on
! cm.5.1 must be a trunk port in order to support overlapping VLANs
vlan make trunk-port cm.5.1
vlan create AMERILINK port-based
vlan create MOONLINK port-based
vlan add ports et.1.1 to AMERILINK
vlan add ports cm.5.1 to AMERILINK
vlan add ports et.1.2 to MOONLINK
vlan add ports cm.5.1 to MOONLINK
interface create ip AMERILINK address-netmask 50.1.1.1/16 vlan
AMERILINK
interface create ip MOONLINK address-netmask 80.1.1.1/16 vlan MOONLINK!
! Bind the client to the VLAN
cmts set modem cm.5.1 macaddr DDEEFF:000002 vlan MOONLINK
cmts set cpe cm.5.1 macaddr 00B0DO:65B463 vlan MOONLINK
cmts set cpe cm.5.1 macaddr 00B0DO:65B464 vlan AMERILINK
et.1.2
et.1.1
cm.5.1
50.1.1.1 80.1.1.1
MOONLINK +
DHCP SERVER
AMERILINK +
DHCP SERVER
DDEEFF: 000002 / 80.2.1.X
MOONLINK MODEM #1
00B0DO: 65B463/80.1.1.X*
MOONLINK CLIENT #1
RS
00B0DO: 65B464 / 50.1.1.X
AMERILINK CLIENT #2