ipv4: Documenting two sysctls for tcp PMTU probe

Namely tcp_probe_interval to control how often to restart
a probe. And tcp_probe_threshold to control when stop the
probing in respect to the width of search range in bytes

Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 1b8c964b0d175c7d86d86896469650e5c59fa689..4412f695a62f493230495114f6c72a87537909b2 100644 (file)
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -388,6 +388,16 @@ tcp_mtu_probing - INTEGER
          1 - Disabled by default, enabled when an ICMP black hole detected
          2 - Always enabled, use initial MSS of tcp_base_mss.
 
+tcp_probe_interval - INTEGER
+       Controls how often to start TCP Packetization-Layer Path MTU
+       Discovery reprobe. The default is reprobing every 10 minutes as
+       per RFC4821.
+
+tcp_probe_threshold - INTEGER
+       Controls when TCP Packetization-Layer Path MTU Discovery probing
+       will stop in respect to the width of search range in bytes. Default
+       is 8 bytes.
+
 tcp_no_metrics_save - BOOLEAN
        By default, TCP saves various connection metrics in the route cache
        when the connection closes, so that connections established in the