tcp.7: Update info on tcp_syn_retries default value

See https://bugzilla.kernel.org/show_bug.cgi?id=202885.

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

diff --git a/man7/tcp.7 b/man7/tcp.7
index 2c4c6f15aa9ea3e70edd53bc9a6616cee1dc551c..5d950951b8a1d3a0682060384cd46c0f9fde8150 100644 (file)
--- a/man7/tcp.7
+++ b/man7/tcp.7
@@ -811,12 +811,18 @@ the urgent pointer:
 the urgent pointer points to the first byte after the urgent data.
 Enabling this option may lead to interoperability problems.
 .TP
-.IR tcp_syn_retries  " (integer; default: 5; since Linux 2.2)"
+.IR tcp_syn_retries  " (integer; default: 6; since Linux 2.2)"
 .\" Since 2.1.38
 The maximum number of times initial SYNs for an active TCP
 connection attempt will be retransmitted.
 This value should not be higher than 255.
-The default value is 5, which corresponds to approximately 180 seconds.
+The default value is 6, which corresponds to retrying for up to
+approximately 127 seconds.
+Before Linux 3.7,
+.\" commit 6c9ff979d1921e9fd05d89e1383121c2503759b9
+the default value was 5, which
+(in conjunction with calculation based on other kernel parameters)
+corresponded to approximately 180 seconds.
 .TP
 .IR tcp_synack_retries " (integer; default: 5; since Linux 2.2)"
 .\" Since 2.1.38