When a client on your internal network sends
a request, the source address in the packet contains the IP address
for the client on your internal network. If you use private IP address
ranges internally, the packets from the client will not be able
to be routed on the Internet unless you translate the source IP
address in the packets leaving the network into a publicly routable
address.
On the firewall you can do this by configuring a
source NAT policy that translates the source address (and optionally
the port) into a public address. One way to do this is to translate
the source address for all packets to the egress interface on your
firewall, as shown in the following procedure.
Beginning with
PAN-OS 10.1.6, you can enable
persistent NAT
for DIPP to mitigate the compatibility issues that symmetric
NAT may have with applications that use STUN.