Network Address Translation

Question

The below given diagram is a Static NAT implementation. To ping from an IPv4 client to an IPv6 client across the router we have to ping the IPv4-mapped address of the corresponding IPv6 client.

For ex:- To ping from PC3 to PC1 we type the command Ping 192.168.2.2 which is the IPv4 mapped address of PC1.

But what we want to do is directly enter the IPv6 address when pinging from PC3 to PC1. ex:- Ping 2001:DB8:AAAA:B::206. The problem is that it is not able to ping by this command.

So is there any technique by which we can communicate from an IPv4 to IPv6 without the use of mapped addresses. The mapping should only take place within the router automatically.

Thank You in advance.

Answer 1

You can't. IPv4 and IPv6 are 2 separate protocols. Without doing some form of protocol translation you cannot access IPv4 resources from IPv6 only hosts and no IPv6 resources from IPv4 only hosts.

Right now there are 3 standard methods:

1. Dual-Stack everything

2. For HTTP (and some other protocols): Use a proxy

3. For a wider variety of protocols implement NAT64 with DNS64. This requires DNS and will not help with pinging IP addresses.

Some older literature will mention NAT-PT which is deprecated and should not be used anymore.

Answer 2

I ping and send packets from an IPv4 address to an IPv6 address by allocating an IPv4 /24 for NAT64 and doing that translation on my NAT64 router which is between the two networks.

I use TAYGA on my dual stack NAT64 router to do the translation and on one of the NAT64 router interfaces it has only an IPv4 address and on the other interface it has only an IPv6 address.

TAYGA has the capability to set manual "mappings" between IPv4 and IPv6 addresses as well as dynamically assign IPv4 addresses for temporary mappings and it works both ways, from IPv4 -> IPv6 and from IPv6 -> IPv4.