Whether IPv6 packets are encapsulated as IPv4 packets by the GRE on the USG6000 to ensure normal communication between two IPv6 networks crossing the IPv4 network

The USG6000 series supports the following IPv6 over IPv4 tunnels: IPv6 over IPv4 manual tunnels IPv6 over IPv4 GRE tunnels IPv6 over IPv4 automatic tunnels 6to4 tunnels 6RD tunnels ISATAP channels

To configure an IPv6 over IPv4 GRE tunnel, perform the following steps: 1. Run the system-view command to enter the system view. 2. Run the interface tunnel interface-number command to create a tunnel interface and enter the tunnel interface view. 3. Run the tunnel-protocol gre command to set the tunnel encapsulation type to GRE tunnel. 4. Run the source { ipv4-address | interface-type interface-number } command to specify the source address or source interface of the GRE tunnel. Note: ?You can directly specify the IPv4 address of the interface used to connect to the IPv4 network as the source address or specify this interface as the source interface. ?You can specify a physical port or a logical interface such as the Loopback interface as the source interface of the tunnel. 5. Run the destination ipv4-address command to specify the destination address or domain name of the GRE tunnel. The destination address is the source address of the peer device. As shown in Figure 1, the destination address of FW_A is 1.1.2.1/24, while the destination address of FW_B is 1.1.1.1/24. 6. Run the ipv6 enable command to enable the IPv6 function on the tunnel interface. 7. Run the ipv6 address { ipv6-address prefix-length | ipv6-address/prefix-length } command to configure the IPv6 address for the tunnel interface. 8. (Optional) Run the gre key key-number command to set the keyword in the GRE packet header. You can set the same key-number on both ends of the tunnel or do not set the key-number.

1. Upon receiving an IP packet over an interface connected to the IP network, the firewall enables the IP processing part to process the IP packet. 2. The IP processing part checks the destination address in the packet header to determine the forwarding mode. If the packet needs to pass through the GRE tunnel to arrive at the destination, the IP processing part sends the packet to the corresponding tunnel interface. 3. Upon receiving the packet, the tunnel interface encapsulates the packet with a GRE packet header and then returns the packet to the IP processing part. 4. The IP processing part encapsulates the GRE packet with a new IP packet header (the source address is the tunnel source interface IP address and the destination address is the tunnel destination interface IP address), and forwards the encapsulated IP packet over the physical port connected to the Internet based on the destination address and routing table.

EOS card by OSN no handle 3 layers protocol,so no handle IPV4 and IPV6.