Hi Daniel, On 08/26/2015 02:02 PM, Daniel Borkmann wrote: > Improve description around tcp_ecn, fix the RFC number and it's not a > boolean anymore since long time, and add a description for tcp_ecn_fallback. > > See also kernel doc under Documentation/networking/ip-sysctl.txt on > tcp_ecn and tcp_ecn_fallback. Thanks for this. > Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> > --- > man7/tcp.7 | 35 ++++++++++++++++++++++++++++++----- > 1 file changed, 30 insertions(+), 5 deletions(-) > > diff --git a/man7/tcp.7 b/man7/tcp.7 > index 2f290a2..0409a66 100644 > --- a/man7/tcp.7 > +++ b/man7/tcp.7 > @@ -396,12 +396,37 @@ option. > .\" Since 2.4.0-test7 > Enable RFC\ 2883 TCP Duplicate SACK support. > .TP > -.IR tcp_ecn " (Boolean; default: disabled; since Linux 2.4)" > +.IR tcp_ecn " (Integer; default: 2; since Linux 2.4)" > .\" Since 2.4.0-test7 > -Enable RFC\ 2884 Explicit Congestion Notification. > -When enabled, connectivity to some > -destinations could be affected due to older, misbehaving > -routers along the path causing connections to be dropped. > +Enable RFC\ 3168 Explicit Congestion Notification. > + > +This file can have one of the following values: > +.RS > +.IP 0 > +Disable ECN. > +Neither initiate nor accept ECN. > +.IP 1 > +Enable ECN when requested by incoming connections and also > +request ECN on outgoing connection attempts. > +.IP 2 > +Enable ECN when requested by incoming connections, > +but do not request ECN on outgoing connections. I also added a note here that option 2 first appeared in Linux 2.6.31. > +.RE > +.IP > +When enabled, connectivity to some destinations could be affected > +due to older, misbehaving middle boxes along the path, causing > +connections to be dropped. > +However, to facilitate and encourage deployment with option 1, and > +to work around such buggy equipment, > +.B tcp_ecn_fallback > +option has been introduced. > +.TP > +.IR tcp_ecn_fallback " (Boolean; default: enabled; since Linux 4.1)" > +.\" commit 492135557dc090a1abb2cfbe1a412757e3ed68ab (Thanks for including the commit ID.) > +Enable RFC\ 3168, Section 6.1.1.1. fallback. > +When enabled, outgoing ECN-setup SYNs that time out within the > +normal SYN retransmission timeout will be resent with CWR and > +ECE cleared. > .TP > .IR tcp_fack " (Boolean; default: enabled; since Linux 2.2)" > .\" Since 2.1.92 Thanks. Applied. Sorry for the delay. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
