tcp.7: Add some version details for 'tcp_ecn' changes

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man7/tcp.7 b/man7/tcp.7
index 0409a66c2211bf753ff15c406323dd37d1eff1a8..737198f15e399434cf1730cf552b8212cca34b55 100644 (file)
--- a/man7/tcp.7
+++ b/man7/tcp.7
@@ -396,7 +396,7 @@ option.
 .\" Since 2.4.0-test7
 Enable RFC\ 2883 TCP Duplicate SACK support.
 .TP
-.IR tcp_ecn " (Integer; default: 2; since Linux 2.4)"
+.IR tcp_ecn " (Integer; default: se below; since Linux 2.4)"
 .\" Since 2.4.0-test7
 Enable RFC\ 3168 Explicit Congestion Notification.
 
@@ -405,12 +405,15 @@ This file can have one of the following values:
 .IP 0
 Disable ECN.
 Neither initiate nor accept ECN.
+This was the default up to and including Linux 2.6.30.
 .IP 1
 Enable ECN when requested by incoming connections and also
 request ECN on outgoing connection attempts.
 .IP 2
+.\" commit 255cac91c3c9ce7dca7713b93ab03c75b7902e0e
 Enable ECN when requested by incoming connections,
 but do not request ECN on outgoing connections.
+This value is supported, and is the default, since Linux 2.6.31.
 .RE
 .IP
 When enabled, connectivity to some destinations could be affected