Source NAT is the translation of the source IP address of a
packet leaving the Juniper Networks device. Source NAT is used to
allow hosts with private IP addresses to access a public network.
The following types of source NAT are supported:
Translation of the original source IP address to the egress
interface’s IP address (also called interface NAT). Port address
translation is always performed.
Translation of the original source IP address to an IP
address from a user-defined address pool without port address translation.
The association between the original source IP address to the translated
source IP address is dynamic. However, once there is an association,
the same association is used for the same original source IP address
for new traffic that matches the same NAT rule.
Translation of the original source IP address to an IP
address from a user-defined address pool with port address translation.
The association between the original source IP address to the translated
source IP address is dynamic. Even if an association exists, the same
original source IP address may be translated to a different address
for new traffic that matches the same NAT rule.
Translation of the original source IP address to an IP
address from a user-defined address pool by shifting the IP addresses.
This type of translation is one-to-one, static, and without port address
translation. If the original source IP address range is larger than
the IP address range in the user-defined pool, untranslated packets
are dropped.
