> On 18. May 2021, at 18:43, Xin Long <lucien.xin@xxxxxxxxx> wrote: > > Hi, Michael, > > We're implementing RFC8899 (PLPMTUD) on Linux SCTP recently, > and to make this be controlled by setsockopt with > SCTP_PEER_ADDR_PARAMS, as in > > https://datatracker.ietf.org/doc/html/rfc6458#section-8.1.12: > > we need another two flags to add for spp_flags: > > SPP_PLPMTUD_ENABLE > SPP_PLPMTUD_DISABLE > > Do you think it makes sense? if yes, does the RFC6458 need to update? > if not, do you have a better suggestion for it? It is great new that you want to implement RFC 8899. I plan to do the same for the FreeBSD stack. In my view, RFC 8899 is the right way to implement PMTU discovery. So I will just use the SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE. I don't think that the user needs to control which method is used. I you want to support multiple versions, I would make that controllable via a sysctl variable. But I think for FreeBSD, support for RFC 8899 will be the only way of doing PMTU discovery. There might be multiple choices for details like how to do the searching, how long to wait for some events. These will be controllable via sysctl. So in my view, there is no need to extend the socket API. What do you think? Best regards Michael > > Thanks.
