CDRouter Support

Testing a CPE in bridge mode

knowledge-base version 12.13


Many broadband access devices, including DSL CPE, DOCSIS gateways, and PON ONUs, can be optionally configured in bridge mode. In bridge mode, the access device simply provides connectivity between the service provider’s DSL, DOCSIS, or PON network and the customer premise. A traditional Ethernet-to-Ethernet gateway is then typically connected to the LAN side of the bridged access device.

A Typical Test Setup

In the diagram above, the DUT is assumed to be a DSL CPE in bridge mode, but this same topology is applicable to other broadband access technologies such as DOCSIS and PON. In this example, CDRouter’s WAN interface (eth1) is directly connected to the DSLAM via Ethernet. Likewise, CDRouter’s LAN interface (eth2) is connected via Ethernet to the LAN side of the DUT. A simple CDRouter configuration based on the following assumptions is provided below.

  • Management interface IPv4 address: DHCP
  • Management interface IPv6 address: DHCPv6
  • Wireless mode: not supported
  • Wireless security: not supported
  • TR-069 support: yes

CDRouter Configuration

# Enable forwarding mode within CDRouter
testvar forwardingMode        bridge

# LAN IPv4 configuration
testvar lanInterface          eth2
testvar lanType               ethernet
testvar dhcpClientStart
testvar dhcpClientEnd 

# WAN IPv4 configuration
testvar wanInterface          eth1
testvar wanMode               DHCP
testvar wanIspIp    
testvar wanIspAssignIp

# IPv6 configuration
testvar supportsIPv6          yes
testvar ipv6WanMode           DHCP
testvar ipv6WanIspIp          3001::1
testvar ipv6WanIspAssignIp    3001::2
testvar ipv6WanIspPrefixLen   64

# TR-069 configuration
testvar supportsCWMP          yes
testvar acsIp       
testvar acsPort               80
testvar acsTransport          http
testvar acsAuth               digest


  • CDRouter Base (IPv4)
  • CDRouter IPv6 (optional, if IPv6 testing is required)
  • CDRouter TR-069 (optional, if the DUT supports TR-069)
  • Two dedicated Ethernet network interfaces
  • One DSL CPE in bridge mode


  • Allows DSL CPE in bridge mode to be tested directly
  • Can be used to verify the forwarding functionality of a DSL CPE in bridge for IPv4 and IPv6
  • Great for verifying TR-069 client functionality in bridge mode

Additional Information

Please see this Application Note for more information on bridge mode testing with CDRouter.

Additional information on testing broadband access devices operating in traditional gateway mode with CDRouter can be found in the following Application Notes:



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