NAT64 Overview
You can configure two types of NAT64 translation on
a Palo Alto Networks® firewall; each one is doing a bidirectional
translation between the two IP address families:
A single IPv4 address can be used for NAT44 and NAT64; you don’t
reserve a pool of IPv4 addresses for NAT64 only.
NAT64 operates on Layer 3 interfaces, subinterfaces, and tunnel
interfaces. To use NAT64 on a Palo Alto Networks firewall for IPv6-initiated
communication, you must have a third-party
DNS64 Server or a solution
in place to separate the DNS query function from the NAT function.
The DNS64 server translates between your IPv6 host and an IPv4 DNS
server by encoding the IPv4 address it receives from a public DNS
server into an IPv6 address for the IPv6 host.
Palo Alto Networks supports the following NAT64 features:
- Persistent NAT
for DIPP
- Hairpinning (NAT U-Turn); additionally, NAT64 prevents hairpinning
loop attacks by dropping all incoming IPv6 packets that have a source
prefix of 64::/n.
- Translation of TCP/UDP/ICMP packets per RFC 6146 and the firewall
makes a best effort to translate other protocols that don’t use
an application-level gateway (ALG). For example, the firewall can
translate a GRE packet. This translation has the same limitation
as NAT44: if you don’t have an ALG for a protocol that can use a
separate control and data channel, the firewall might not understand
the return traffic flow.
- Translation between IPv4 and IPv6 of the ICMP length attribute
of the original datagram field, per RFC 4884.
