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Diffstat (limited to 'Documentation/networking/ip-sysctl.rst')
| -rw-r--r-- | Documentation/networking/ip-sysctl.rst | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 6ec06a33688a..4a010a7cde7f 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -881,9 +881,10 @@ tcp_fastopen_key - list of comma separated 32-digit hexadecimal INTEGERs tcp_syn_retries - INTEGER Number of times initial SYNs for an active TCP connection attempt will be retransmitted. Should not be higher than 127. Default value - is 6, which corresponds to 63seconds till the last retransmission - with the current initial RTO of 1second. With this the final timeout - for an active TCP connection attempt will happen after 127seconds. + is 6, which corresponds to 67seconds (with tcp_syn_linear_timeouts = 4) + till the last retransmission with the current initial RTO of 1second. + With this the final timeout for an active TCP connection attempt + will happen after 131seconds. tcp_timestamps - INTEGER Enable timestamps as defined in RFC1323. @@ -946,6 +947,16 @@ tcp_pacing_ca_ratio - INTEGER Default: 120 +tcp_syn_linear_timeouts - INTEGER + The number of times for an active TCP connection to retransmit SYNs with + a linear backoff timeout before defaulting to an exponential backoff + timeout. This has no effect on SYNACK at the passive TCP side. + + With an initial RTO of 1 and tcp_syn_linear_timeouts = 4 we would + expect SYN RTOs to be: 1, 1, 1, 1, 1, 2, 4, ... (4 linear timeouts, + and the first exponential backoff using 2^0 * initial_RTO). + Default: 4 + tcp_tso_win_divisor - INTEGER This allows control over what percentage of the congestion window can be consumed by a single TSO frame. @@ -970,6 +981,21 @@ tcp_tw_reuse - INTEGER tcp_window_scaling - BOOLEAN Enable window scaling as defined in RFC1323. +tcp_shrink_window - BOOLEAN + This changes how the TCP receive window is calculated. + + RFC 7323, section 2.4, says there are instances when a retracted + window can be offered, and that TCP implementations MUST ensure + that they handle a shrinking window, as specified in RFC 1122. + + - 0 - Disabled. The window is never shrunk. + - 1 - Enabled. The window is shrunk when necessary to remain within + the memory limit set by autotuning (sk_rcvbuf). + This only occurs if a non-zero receive window + scaling factor is also in effect. + + Default: 0 + tcp_wmem - vector of 3 INTEGERs: min, default, max min: Amount of memory reserved for send buffers for TCP sockets. Each TCP socket has rights to use it due to fact of its birth. @@ -1352,8 +1378,8 @@ ping_group_range - 2 INTEGERS Restrict ICMP_PROTO datagram sockets to users in the group range. The default is "1 0", meaning, that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions - to the single group. "0 4294967295" would enable it for the world, "100 - 4294967295" would enable it for the users, but not daemons. + to the single group. "0 4294967294" would enable it for the world, "100 + 4294967294" would enable it for the users, but not daemons. tcp_early_demux - BOOLEAN Enable early demux for established TCP sockets. |