On Tue, Oct 20, 2020 at 11:15:26PM +0200, Michael Tuexen wrote: > > On 20. Oct 2020, at 23:11, Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> wrote: > > > > On Tue, Oct 20, 2020 at 05:12:06PM +0800, Xin Long wrote: > >> On Tue, Oct 20, 2020 at 6:15 AM Marcelo Ricardo Leitner > >> <marcelo.leitner@xxxxxxxxx> wrote: > >>> > >>> On Mon, Oct 19, 2020 at 08:25:33PM +0800, Xin Long wrote: > >>>> --- a/Documentation/networking/ip-sysctl.rst > >>>> +++ b/Documentation/networking/ip-sysctl.rst > >>>> @@ -2640,6 +2640,12 @@ addr_scope_policy - INTEGER > >>>> > >>>> Default: 1 > >>>> > >>>> +udp_port - INTEGER > >>> > >>> Need to be more verbose here, and also mention the RFC. > >>> > >>>> + The listening port for the local UDP tunneling sock. > >>> , shared by all applications in the same net namespace. > >>>> + UDP encapsulation will be disabled when it's set to 0. > >>> > >>> "Note, however, that setting just this is not enough to actually > >>> use it. ..." > >> When it's a client, yes, but when it's a server, the encap_port can > >> be got from the incoming packet. > >> > >>> > >>>> + > >>>> + Default: 9899 > >>>> + > >>>> encap_port - INTEGER > >>>> The default remote UDP encapsalution port. > >>>> When UDP tunneling is enabled, this global value is used to set > >>> > >>> When is it enabled, which conditions are needed? Maybe it can be > >>> explained only in the one above. > >> Thanks! > >> pls check if this one will be better: > > > > It is. Verbose enough now, thx. > > (one other comment below) > > > >> > >> udp_port - INTEGER > >> > >> The listening port for the local UDP tunneling sock. > >> > >> This UDP sock is used for processing the incoming UDP-encapsulated > >> SCTP packets (from RFC6951), and shared by all applications in the > >> same net namespace. This UDP sock will be closed when the value is > >> set to 0. > >> > >> The value will also be used to set the src port of the UDP header > >> for the outgoing UDP-encapsulated SCTP packets. For the dest port, > >> please refer to 'encap_port' below. > >> > >> Default: 9899 > > > > I'm now wondering if this is the right default. I mean, it is the > > standard port for it, yes, but at the same time, it means loading SCTP > > module will steal/use that UDP port on all net namespaces and can lead > > to conflicts with other apps. A more conservative approach here is to > > document the standard port, but set the default to 0 and require the > > user to set it in if it is expected to be used. > > > > Did FreeBSD enable it by default too? > No. The default is 0, which means that the encapsulation is turned off. > Setting this sysctl variable to a non-zero value enables the UDP tunneling > with the given port. Thanks Michael. Xin, then we should change this default value (and update the documentation above accordingly, to still have the standard port # readily available in there). Cheers, Marcelo
