IPv4 and IPv6 coexistence

Problem statement

As IPv6 adoption is increased on the internet, there can be situations where a network operating on IPv4 is connected to the next network operating on IPv6. Here, the problem lies in the difference in the packet structures of both protocols. The transmission across the network layer with different protocols can lose data of the packet fields. There are multiple solutions available to tackle this issue. Some of them are:

• Dual stack
• 6 to 4 or 4 to 6 tunnels
• NAT-PT (also called NAT64)

Dual stack

The dual stack concept is very simple. All we have to do is configure two IP addresses (one being a v4 and the other v6) on our device (router, PC, server, and so on). This way, the devices will be able to talk to each other by using any of the two protocols.

For example, PC1, PC2, and R1 have both IP addresses (v4 and v6) as shown below.