vxlan(4) actually supports IPv6 tunnel endpoints. Only multicast endpoints are unsupported.
Index: vxlan.4 =================================================================== RCS file: /cvs/src/share/man/man4/vxlan.4,v retrieving revision 1.8 diff -u -p -r1.8 vxlan.4 --- vxlan.4 22 Nov 2018 17:31:11 -0000 1.8 +++ vxlan.4 26 Jun 2020 11:52:32 -0000 @@ -176,4 +176,5 @@ decreased MTU of 1450 bytes. In any other case, it is commonly recommended to set the MTU of the transport interfaces to at least 1600 bytes. .Pp -The implementation does not support IPv6 tunnel endpoints at present. +The implementation does not support IPv6 multicast tunnel endpoints at +present.
