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| author | sbruno <sbruno@FreeBSD.org> | 2015-08-12 22:51:08 +0000 |
|---|---|---|
| committer | sbruno <sbruno@FreeBSD.org> | 2015-08-12 22:51:08 +0000 |
| commit | 3e1f1ceab6f729496c14d5168e17d7aa4cb13f12 (patch) | |
| tree | 13170b0601e94cc2c0b2a614f8584babddba14ca /share | |
| parent | 3ab328cd1c4acb10f53d39b000d9960bd7df4680 (diff) | |
| download | FreeBSD-src-3e1f1ceab6f729496c14d5168e17d7aa4cb13f12.zip FreeBSD-src-3e1f1ceab6f729496c14d5168e17d7aa4cb13f12.tar.gz | |
MFC r273081
brueffer: New sentence -> new line; use macros where appropriate.
MFC r276345
Mikhail <mp@lenta.ru
Correct naming of sysctl pmtud_blackhole_activated_min_mss.
Clarify some statements around PMTUD blackhole detection to make
the behavior more clear in the man page.
Diffstat (limited to 'share')
| -rw-r--r-- | share/man/man4/tcp.4 | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/share/man/man4/tcp.4 b/share/man/man4/tcp.4 index dd218bc..7ad9f48 100644 --- a/share/man/man4/tcp.4 +++ b/share/man/man4/tcp.4 @@ -520,23 +520,31 @@ ECN allows a TCP sender to reduce the transmission rate in order to avoid packet drops. .It Va ecn.maxretries Number of retries (SYN or SYN/ACK retransmits) before disabling ECN on a -specific connection. This is needed to help with connection establishment +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). +Turn on automatic path MTU blackhole detection. +In case of retransmits OS 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 configured value, otherwise, +MSS will be set to default values +.Po Va net.inet.tcp.mssdflt +and +.Va net.inet.tcp.v6mssdflt +.Pc . .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. +Number of times configured values were used in an attempt to downshift. +.It Va pmtud_blackhole_activated_min_mss +Number of times default 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. +Number of connections for which retransmits continued even after MSS +downshift. .El .Sh ERRORS A socket operation may fail with one of the following errors returned: |
