Hi! After banging my head over a problem (I can't seem to be able to successfully establish an IPv6 tunnel over IPv6 with gre(4)), I consulted chatgpt.com (I know, I know...). On there, the AI model states that gre(4) only supports tunneling over IPv4. After reading the man page, I came across the following paragraph:
"The gre pseudo-device provides interfaces for tunnelling protocols across IPv4 and IPv6 networks using the Generic Routing Encapsulation (GRE) encapsulation protocol." I read this as IPv6 over IPv6 *is* possible; but at the same time, there is only a sysctl switch "net.inet.gre.allow", whereas other sysctl switches, enabling different IPv6 routing capabilities, use "net.inet6[...]". So? Thank you for your time and clarifying the issue... -- Mit besten Wünschen / With best wishes, Manuel Kuklinski