Hi, On Thu, Oct 26, 2023 at 9:56 AM Michael Richardson <mcr@xxxxxxxxxxxx> wrote: > > > Alexander Aring <aahringo@xxxxxxxxxx> wrote: > >> Mathis Marion <mathis.marion@xxxxxxxxxx> wrote: > However, my > >> observations suggest that it is actually not the case when > > >> forwarding packets. Instead, the IPv6 header of the packet is modified > >> > in a way which violates the IPv6 specification (RFC 8200 section 4): > >> > >> I have not sat down to read the code to understand what it actually > >> does, so I can't really comment at this point. I salute you for > >> having gotten into whether the code is compliant. > >> > >> But, I did write spend way too much of my life writing > >> https://datatracker.ietf.org/doc/rfc9008/ to deal with the perception > >> that RPL networks had to violate 8200. > >> > >> I know that Linux does not (yet) deal with all the minutia in 9008. I > >> wish that I had time to fix that. > > > To put everything into IPIP and back is not a question of doing a > > iptunnel ip6tnl [0] and doing the right configuration... just do get > > everything over "the internet" which I think is the whole reason why > > putting everything into IPIP? > > I agree that modelling it an infinite series of iptunnel/ip6tnl is the wrong approach. > I would model it akin to how ND and ARP work: something that happens which > then resolves into some bytes that get prefixed and/or removed. then it is currently possible, but not in a nice way (you will configure yourself to death)... there might be new config options of iptunnel/ip6tnl to do your ND approach (maybe with accessing ND cache?). It is not that the rpl tunnel for source routing header needs to deal with IP6IP6, it already exists in the kernel with ip6tnl implementation... it's just terrible to configure it. - Alex
