Yes, you can make hybrid networks that use both IPv4 and IPv6, and this is quite common as we transition to broader adoption of IPv6.

These hybrid networks are necessary because IPv4 and IPv6 are incompatible protocols with each other, meaning they cannot communicate directly.

Here we summarize how this interoperability can be achieved:

1. Dual Stack

The most common strategy for managing hybrid networks is the “Dual Stack” approach, where network devices are configured to operate with both protocols (IPv4 and IPv6) simultaneously.

Each device on a dual stack network has both an IPv4 and an IPv6 address, and can send and receive traffic using either protocol, depending on the availability and configuration of the destination network.

This allows for a smooth coexistence and transition between the two protocols.

2. Tunnels

Tunnels are another technique used to connect IPv6 networks over predominantly IPv4 infrastructure.

This involves encapsulating IPv6 packets within IPv4 packets so that they can be sent over networks that only support IPv4.

There are several tunneling methods such as 6to4, Teredo, and ISATAP, each with their own specific use cases and configuration considerations.

3. Protocol Address Translation (NAT-PT)

NAT-PT (Network Address Translation – Protocol Translation) is a translation mechanism that allows direct communication between hosts using IPv4 and IPv6.

This technique translates addresses and packet format from one protocol to another. However, due to complications in session translation and maintenance, as well as limitations in support for certain protocols and applications, NAT-PT has been largely discouraged and replaced by better solutions such as NAT64.

4. NAT64/DNS64

NAT64 in combination with DNS64 is a more modern technique that allows IPv6 devices to communicate with IPv4 servers. DNS64 synthesizes AAAA (IPv6) records from available A (IPv4) records, allowing IPv6 devices to address IPv4 servers as if they were IPv6. NAT64 then translates the IPv6 address of the outgoing packet into an IPv4 address to allow communication with the IPv4 network.

These techniques enable a gradual transition and coexistence of IPv4 and IPv6, ensuring that networks and services can continue to operate while moving towards broader adoption of IPv6.