Overview
In this model we see that NAT has been moved from the CPE to the ISP. The CPE is now a Basic Bridging BroadBand element (B4), in DS-Lite terminology. The ISP end, perhaps amusingly, is named the AFTR (Address Family Transition Router). Packets with private addresses leave the B4 CPE untranslated. After decapsulation by the AFTR, they have NAT applied and are routed onto the IPv4 Internet. Users with IPv4 only devices will effectively see no changes from the current model of CPE based NAT. Media devices, LAN enabled smart phones, gaming consoles, laptops and workstations alike will continue operating with zero configuration changes. This model is desirable because it mitigates support costs to everyone: ISPs will have fewer consumer support issues, and businesses will have smaller network administration costs.
Test Setup
CDRouter Configuration
# -- IPv4 Configuration:
# WAN configuration
testvar wanInterface eth2
testvar wanMode dslite
testvar wanIspIp 192.0.0.1
testvar wanIspAssignIp 192.0.0.2
testvar RemoteHost 3.3.3.3
# LAN configuration
testvar lanInterface eth1
testvar lanIp 192.168.1.1
testvar lanMask 255.255.255.0
testvar dhcpClientStart 192.168.1.2
testvar dhcpClientEnd 192.168.1.7
# -- IPv6 Configuration:
testvar supportsIPv6 yes
# WAN configuration
testvar ipv6WanMode DHCP
testvar ipv6WanIspIp 3001::1
testvar ipv6WanIspAssignIp 3001::2
testvar ipv6WanIspNextIp 3001::3
testvar ipv6WanIspPrefixLen 64
testvar dhcpv6WanEnablePD yes
testvar dhcpv6WanAssignPrefix 3001:dddd::
testvar dhcpv6WanAssignNextPrefix 3001:ddde::
testvar dhcpv6WanAssignPrefixLen 48
testvar dhcpv6PDLatency 30
# DS-Lite AFTR configuration
testvar ipv6DsliteAftr 3001:aaaa::1
testvar dhcpv6WanAftrName aftr.qacafe.com
# LAN configuration
testvar ipv6LanMode autoconf
testvar ipv6LanIp ::1
testvar ipv6LanSubnetId 1
testvar ipv6WanDnsServer 3001:51a:cafe::2
testvar ipv6WanBackupDnsServer 3001:51a:cafe::3
# other configuration options
testvar ipv6RemoteHost 3001:51a:cafe::1
testvar ipv6FreeNetworkStart 3001:cafe:1::
testvar ipv6FreeNetworkEnd 3001:cafe:ffff::
testvar ipv6FreeNetworkPrefixLen 64
Requirements
- CDRouter or CDRouter Multiport
- The CDRouter IPv6 add-on module
- Two dedicated Ethernet network interfaces
- One dual-stack router with DS-Lite support
Benefits
- Simple setup, great for a stand-alone test station
- Allows DS-Lite enabled devices to be tested in isolation
- Perfect for debugging test failures and testing functionality in a dual-stack environment
- Useful for ensuring IPv4 connectivity when IPv6 WAN connection renumbers
- Useful for verifying IPv4 and NAT related functionality in a DS-Lite environment
Additional Information
Please see the CDRouter IPv6 User’s Guide and our Application Note on DS-Lite for more information.
