OK, let's assume we have
an IP subnet N,
a host H in N,
a host G in N and
a host A outside of N.
Packets from H to A go via G, since H is configured as gateway on H.
How save is it to assume that all packets from A to H (the other way
round) go via G?
I'm looking real world examples where a packet enters an IP subnet on
one way (interface) and an answering packet leaves N on another way
(different interface). Only load-balancing or dedicated firewalls
come to my mind. Is such an environment found often? Are the other