Simple NAT64 Setup

Configuring a Proxy server with IPv6/IPv4 connectivity will not enable IPv6 only users to access resources other that web (http, https, ftp etc). For example a printer with Ipv4 only connectivity or a POP server with Ipv4 only will not be accessible through a proxy server. What you can do to enable IPv4 accessibility from IPv6 only network?

When we had this issue we thought of implementing NAT-PT server in our IPv6 network but as stated NAT -PT is depreciate by RFC 4966 due to number of issues in NAT-PT

Then we tried NAT64 with DNS64. We obtained an open source NAT64 gateway live CD from Ecdysis http://ecdysis.viagenie.ca/ and installed it on a server. It is running on a customized fedora OS. The system architecture of NAT64 can be given as follows.

+-------------+
                            +-------------------------+IPv6 Internet|
                            |                         +-------------+
                            |          +-----+
                 +------+   |     +----+NAT64+----+
       IPv6 host-+      |   |    /     +-----+     \  +-------------+
                 | CPE  +--IPv6-<                   >-+IPv4 Internet|
       IPv6 host-+router|        \ +-------------+ /  +-------------+
                 +------+         ++DNS rewriting|+
                                   +-------------+

This is from http://www.viagenie.ca/ietf/draft/draft-wing-nat-pt-replacement-comparison-02.txt 

The steps we followed in configuring NAT64/DNS64 are as follows

Settings at the NAT64/DNS64 Gateway

• Install the NAT64 server on a PC with 2 interface cards
• Login to the server and configure the interfaces with IPv4 and IPv6 addresses according to the network setup
• Run the provided script magic-quick-start.sh
• Check the network configurations 
• You should observe a nat64 interface when you run ifconfig

• Set the firewall rules in iptables and ip6tables
• This is important as many attacks may come thro

Settings at your IPv6 clients

• Set the DNS server as the NAT64 servers IPv6 address
• Add a route for 64:ff9b::/64 to the NAT64 gateway IPv6 address

After all you can verify the settings at the clients end by querying IPv4 only resource with AAAA

e.g. dig chamaradisanayake.blogspot.com AAAA

(Here chamaradisanayake.blogspot.com does not have IPv6 address but we are asking to get an IPv6 address from the NAT64/DNS64 gateway)

If every thing is fine you should get an answer as 

chamaradisanayake.blogspot.com. 929 IN CNAME blogspot.l.google.com.

blogspot.l.google.com. 139 IN AAAA 64:ff9b::d155:af84

Here 64:ff9b:: is the DNS prefix added by the DNS64 server and d155:af84 is hexadecimal representation of IPv4 address of chamaradisanayake.blogspot.com