Configure IPv4 over IPv6 Tunnel

Configuration Conditions

Before configuring the IPv4 over IPv6 tunnel, complete the following tasks:

Configure the IP4 address of the interface, making the neighboring nodes reachable at the network layer.
Create one tunnel interface, and configure the basic parameters (refer to the configuration manual of the tunnel interface).
Configure any unicast routing protocol, making the route at the two ends of the tunnel reachable.

Table 12-2 Configure IPv4 over IPv6 tunnel

Step	Command	Description
Enter the global configuration mode	configure terminal	-
Enter the tunnel configuration mode	interface tunnel tunnel-number	-
Configure the tunnel interface address	ip address ip-address { mask \| mask-length }	Mandatory By default, the address is not configured on the tunnel interface.
Configure the Tunnel interface mode as IPv4 over IPv6	tunnel mode ipv4ipv6	Optional By default, the mode of the Tunnel interface is GRE over IPv4.
Configure the source address or interface name of the Tunnel interface	tunnel source { ipv6-address \| interface-name }	Mandatory By default, do not configure the source address or interface name on the tunnel interface.
Configure the destination address of the Tunnel interface	tunnel destination { ipv6-address }	Mandatory By default, the destination address is not configured on Tunnel interface.

The tunnel interface address needs to be configured with IPv4 address, and the protocol can only be IPv4 protocol.
The two ends of the tunnel must be configured with the source IP address and the destination IP address. The IP addresses at the start and end of the tunnel are complementary source IP address and destination IP address for each other.
When configuring the tunnel source and if the interface mode is adopted, the source address of the tunnel adopts the first IPv6 address of the source interface (non-linklocal address).
The start and end of the tunnel must be configured with the same tunnel mode. Otherwise, the tunnel transmission fails.