Configuration restrictions and guidelines
Follow these guidelines when you configure an IPv4 over IPv6 manual tunnel:
The tunnel destination address specified on the local device must be identical with the tunnel source address specified on the tunnel peer device.
Do not specify the same source and destination addresses for local tunnel interfaces in the same tunnel mode.
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.