Configuration restrictions and guidelines
A B4 tunnel interface can establish a tunnel with only one AFTR tunnel interface, but an AFTR tunnel interface can establish tunnels with multiple B4 tunnel interfaces.
Follow these guidelines when you configure the B4 router of a DS-Lite tunnel:
Do not specify the same source addresses for local tunnel interfaces in the same tunnel mode.
The destination address specified for the tunnel interface on the B4 router must be the source address specified for the tunnel interface on the AFTR.
To ensure correct packet forwarding, identify whether the destination IPv4 network and the IPv4 address of the local tunnel interface are on the same subnet. If they are not, configure a route reaching the destination IPv4 network through the tunnel interface. You can configure the route by using one of the following methods:
Configure a static route, and specify the local tunnel interface as the egress interface or specify the IPv6 address of the peer tunnel interface as the next hop.
Enable a dynamic routing protocol on both tunnel interfaces to achieve the same purpose.
For more information about route configuration, see Layer 3—IP Routing Configuration Guide.
Follow these guidelines when you configure the AFTR of a DS-Lite tunnel:
Do not specify the same source addresses for local tunnel interfaces in the same tunnel mode.
Enable NAT on the interface that is connected to the public IPv4 interface.
The tunnel destination cannot be configured on the AFTR. The AFTR uses the address of the B4 router as the IPv6 address of the tunnel destination.
It is not necessary to configure a route to the destination IPv4 address for forwarding packets through the tunnel interface.