path: root/Documentation/networking
diff options
authorFan Du <>2015-03-06 11:18:25 +0800
committerDavid S. Miller <>2015-03-06 14:57:42 -0500
commitfab42760843734a82b6b2d1241ca44f375a686eb (patch)
treeedd39a71398f8639e3166dd64805399c5a8cec11 /Documentation/networking
parent05cbc0db03e82128f2e7e353d4194dd24a1627fe (diff)
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 <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'Documentation/networking')
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 1b8c964b0d17..4412f695a62f 100644
--- 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