svn commit: r273061 - head/share/man/man4

[Sean Bruno]

Author: sbruno
Date: Mon Oct 13 21:04:14 2014
New Revision: 273061
URL: https://svnweb.freebsd.org/changeset/base/273061

Log:
  Update tcp(4) with plpmtud blackhole sysctls
  
  Submitted by:	Mikhail <mp at lenta.ru>
  MFC after:	2 weeks
  Relnotes:	yes

Modified:
  head/share/man/man4/tcp.4

Modified: head/share/man/man4/tcp.4
==============================================================================
--- head/share/man/man4/tcp.4	Mon Oct 13 20:39:51 2014	(r273060)
+++ head/share/man/man4/tcp.4	Mon Oct 13 21:04:14 2014	(r273061)
@@ -518,6 +518,21 @@ avoid packet drops.
 Number of retries (SYN or SYN/ACK retransmits) before disabling ECN on a
 specific connection. This is needed to help with connection establishment
 when a broken firewall is in the network path.
+.It Va pmtud_blackhole_detection
+Turn on automatic path MTU blackhole detection. In case of retransmits we will
+lower the MSS to check if it's MTU problem. If current MSS is greater than
+configured value to try, it will be set to it, otherwise, MSS will be set to
+default values (net.inet.tcp.mssdflt and net.inet.tcp.v6mssdflt).
+.It Va pmtud_blackhole_mss
+MSS to try for IPv4 if PMTU blackhole detection is turned on.
+.It Va v6pmtud_blackhole_mss
+MSS to try for IPv6 if PMTU blackhole detection is turned on.
+.It Va pmtud_blackhole_activated
+Number of times the code was activated to attempt a MSS downshift.
+.It Va pmtud_blackhole_min_activated
+Number of times the blackhole MSS was used in an attempt to downshift.
+.It Va pmtud_blackhole_failed
+Number of times that we failed to connect after we downshifted the MSS.
 .El
 .Sh ERRORS
 A socket operation may fail with one of the following errors returned: