Maybe for those not aware of the "private" address ranges that should
not be sent outside their own network, here they are:
127.0.0.0/8 - loopback addresses per RFC1122
10.0.0.0/16 - private single class A network per RFC 1918
172.16.0.0/12 - private 16 class B networks per RFC 1918
192.168.0.0/16 - private 256 class C networks per RFC 1918
169.254.0.0/16 - link-local (zero conf) address space per RFC 3927
44.128.0.0/16 - test address space as defined by the AMPR network
None of these addresses shall ever leave your local network under any
circumstances.
For additional info:
https://tools.ietf.org/html/rfc6890
Marius, YO2LOJ