Despite open5gs allowing to change the GTP ports in the config file, in
reality changing those values to something else than the standard prot
will fail. Hence, we must use the standard port. As a result, we must
use different IP addresses in each process to avoid ip+port collisions.
Let's use some loopback addresses which shouldn't require extra
configuration on the host, and still only requiring 1 run_node as per
existing EPCs, with the limitation that only 1 open5gs EPC instance can
be run at one in a given run_node.
Related: https://github.com/open5gs/open5gs/issues/897
Change-Id: Id3062c6ad9d6de4c6066547e1e46edad5da285c1
Andre Puschmann
Pau Espin