RBR850 NAT loopback

This link is to an idea forum where new things are being proposed.

Being unable to establish a connection to a port on the public Internet is a bug.

Please read RFC 5382

7.2. Hairpinning Behavior

NATs that forward packets originating from an internal address,
destined for an external address that matches the active mapping for
an internal address, back to that internal address are defined in
[BEHAVE-UDP] as supporting "hairpinning". If the NAT presents the
hairpinned packet with an external source IP address and port (i.e.,
the mapped source address and port of the originating internal
endpoint), then it is defined to have "External source IP address and
port" for hairpinning. Hairpinning is necessary to allow two
internal endpoints (known to each other only by their external mapped
addresses) to communicate with each other. "External source IP
address and port" behavior for hairpinning avoids confusing
implementations that expect the external source IP address and port.

REQ-8: A NAT MUST support "hairpinning" for TCP.

a) A NAT's hairpinning behavior MUST be of type "External source
IP address and port".

Justification: This requirement allows two applications behind the
same NAT that are trying to communicate with each other using
their external addresses.

a) Using the external source address and port for the hairpinned
packet is necessary for applications that do not expect to
receive a packet from a different address than the external
address they are trying to communicate with.