#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: man-pages-l10n VERSION\n"
"POT-Creation-Date: 2014-07-17 17:57+0900\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. type: TH
#: man-pages/man7/tcp.7:76
#, no-wrap
msgid "TCP"
msgstr ""

#. type: TH
#: man-pages/man7/tcp.7:76
#, no-wrap
msgid "2014-03-31"
msgstr ""

#. type: TH
#: man-pages/man7/tcp.7:76
#, no-wrap
msgid "Linux"
msgstr ""

#. type: TH
#: man-pages/man7/tcp.7:76
#, no-wrap
msgid "Linux Programmer's Manual"
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:77
#, no-wrap
msgid "NAME"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:79
msgid "tcp - TCP protocol"
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:79
#, no-wrap
msgid "SYNOPSIS"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:81
msgid "B<#include E<lt>sys/socket.hE<gt>>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:83
msgid "B<#include E<lt>netinet/in.hE<gt>>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:85
msgid "B<#include E<lt>netinet/tcp.hE<gt>>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:87
msgid "B<tcp_socket = socket(AF_INET, SOCK_STREAM, 0);>"
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:87
#, no-wrap
msgid "DESCRIPTION"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:100
msgid ""
"This is an implementation of the TCP protocol defined in RFC\\ 793, RFC\\ "
"1122 and RFC\\ 2001 with the NewReno and SACK extensions.  It provides a "
"reliable, stream-oriented, full-duplex connection between two sockets on top "
"of B<ip>(7), for both v4 and v6 versions.  TCP guarantees that the data "
"arrives in order and retransmits lost packets.  It generates and checks a "
"per-packet checksum to catch transmission errors.  TCP does not preserve "
"record boundaries."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:119
msgid ""
"A newly created TCP socket has no remote or local address and is not fully "
"specified.  To create an outgoing TCP connection use B<connect>(2)  to "
"establish a connection to another TCP socket.  To receive new incoming "
"connections, first B<bind>(2)  the socket to a local address and port and "
"then call B<listen>(2)  to put the socket into the listening state.  After "
"that a new socket for each incoming connection can be accepted using "
"B<accept>(2).  A socket which has had B<accept>(2)  or B<connect>(2)  "
"successfully called on it is fully specified and may transmit data.  Data "
"cannot be transmitted on listening or not yet connected sockets."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:139
msgid ""
"Linux supports RFC\\ 1323 TCP high performance extensions.  These include "
"Protection Against Wrapped Sequence Numbers (PAWS), Window Scaling and "
"Timestamps.  Window scaling allows the use of large (E<gt> 64K) TCP windows "
"in order to support links with high latency or bandwidth.  To make use of "
"them, the send and receive buffer sizes must be increased.  They can be set "
"globally with the I</proc/sys/net/ipv4/tcp_wmem> and I</proc/sys/net/ipv4/"
"tcp_rmem> files, or on individual sockets by using the B<SO_SNDBUF> and "
"B<SO_RCVBUF> socket options with the B<setsockopt>(2)  call."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:170
msgid ""
"The maximum sizes for socket buffers declared via the B<SO_SNDBUF> and "
"B<SO_RCVBUF> mechanisms are limited by the values in the I</proc/sys/net/"
"core/rmem_max> and I</proc/sys/net/core/wmem_max> files.  Note that TCP "
"actually allocates twice the size of the buffer requested in the "
"B<setsockopt>(2)  call, and so a succeeding B<getsockopt>(2)  call will not "
"return the same size of buffer as requested in the B<setsockopt>(2)  call.  "
"TCP uses the extra space for administrative purposes and internal kernel "
"structures, and the I</proc> file values reflect the larger sizes compared "
"to the actual TCP windows.  On individual connections, the socket buffer "
"size must be set prior to the B<listen>(2)  or B<connect>(2)  calls in order "
"to have it take effect.  See B<socket>(7)  for more information."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:202
msgid ""
"TCP supports urgent data.  Urgent data is used to signal the receiver that "
"some important message is part of the data stream and that it should be "
"processed as soon as possible.  To send urgent data specify the B<MSG_OOB> "
"option to B<send>(2).  When urgent data is received, the kernel sends a "
"B<SIGURG> signal to the process or process group that has been set as the "
"socket \"owner\" using the B<SIOCSPGRP> or B<FIOSETOWN> ioctls (or the POSIX."
"1-2001-specified B<fcntl>(2)  B<F_SETOWN> operation).  When the "
"B<SO_OOBINLINE> socket option is enabled, urgent data is put into the normal "
"data stream (a program can test for its location using the B<SIOCATMARK> "
"ioctl described below), otherwise it can be received only when the "
"B<MSG_OOB> flag is set for B<recv>(2)  or B<recvmsg>(2)."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:210
msgid ""
"Linux 2.4 introduced a number of changes for improved throughput and "
"scaling, as well as enhanced functionality.  Some of these features include "
"support for zero-copy B<sendfile>(2), Explicit Congestion Notification, new "
"management of TIME_WAIT sockets, keep-alive socket options and support for "
"Duplicate SACK extensions."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:210
#, no-wrap
msgid "Address formats"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:219
msgid ""
"TCP is built on top of IP (see B<ip>(7)).  The address formats defined by "
"B<ip>(7)  apply to TCP.  TCP supports point-to-point communication only; "
"broadcasting and multicasting are not supported."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:219
#, no-wrap
msgid "/proc interfaces"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:231
msgid ""
"System-wide TCP parameter settings can be accessed by files in the directory "
"I</proc/sys/net/ipv4/>.  In addition, most IP I</proc> interfaces also apply "
"to TCP; see B<ip>(7).  Variables described as I<Boolean> take an integer "
"value, with a nonzero value (\"true\") meaning that the corresponding option "
"is enabled, and a zero value (\"false\")  meaning that the option is "
"disabled."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:231
#, no-wrap
msgid "I<tcp_abc> (Integer; default: 0; since Linux 2.6.15)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:239
msgid ""
"Control the Appropriate Byte Count (ABC), defined in RFC 3465.  ABC is a way "
"of increasing the congestion window (I<cwnd>)  more slowly in response to "
"partial acknowledgments.  Possible values are:"
msgstr ""

#. type: IP
#: man-pages/man7/tcp.7:240 man-pages/man7/tcp.7:428 man-pages/man7/tcp.7:449 man-pages/man7/tcp.7:593
#, no-wrap
msgid "0"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:244
msgid "increase I<cwnd> once per acknowledgment (no ABC)"
msgstr ""

#. type: IP
#: man-pages/man7/tcp.7:244 man-pages/man7/tcp.7:430 man-pages/man7/tcp.7:456 man-pages/man7/tcp.7:595
#, no-wrap
msgid "1"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:248
msgid "increase I<cwnd> once per acknowledgment of full sized segment"
msgstr ""

#. type: IP
#: man-pages/man7/tcp.7:248 man-pages/man7/tcp.7:432 man-pages/man7/tcp.7:463 man-pages/man7/tcp.7:597
#, no-wrap
msgid "2"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:253
msgid ""
"allow increase I<cwnd> by two if acknowledgment is of two segments to "
"compensate for delayed acknowledgments."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:254
#, no-wrap
msgid "I<tcp_abort_on_overflow> (Boolean; default: disabled; since Linux 2.4)"
msgstr ""

#.  Since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:266
msgid ""
"Enable resetting connections if the listening service is too slow and unable "
"to keep up and accept them.  It means that if overflow occurred due to a "
"burst, the connection will recover.  Enable this option I<only> if you are "
"really sure that the listening daemon cannot be tuned to accept connections "
"faster.  Enabling this option can harm the clients of your server."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:266
#, no-wrap
msgid "I<tcp_adv_win_scale> (integer; default: 2; since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:278
msgid ""
"Count buffering overhead as I<bytes/2^tcp_adv_win_scale>, if "
"I<tcp_adv_win_scale> is greater than 0; or I<bytes-bytes/2^(-"
"tcp_adv_win_scale)>, if I<tcp_adv_win_scale> is less than or equal to zero."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:291
msgid ""
"The socket receive buffer space is shared between the application and kernel."
"  TCP maintains part of the buffer as the TCP window, this is the size of "
"the receive window advertised to the other end.  The rest of the space is "
"used as the \"application\" buffer, used to isolate the network from "
"scheduling and application latencies.  The I<tcp_adv_win_scale> default "
"value of 2 implies that the space used for the application buffer is one "
"fourth that of the total."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:291
#, no-wrap
msgid ""
"I<tcp_allowed_congestion_control> (String; default: see text; since Linux 2."
"4.20)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:304
msgid ""
"Show/set the congestion control algorithm choices available to unprivileged "
"processes (see the description of the B<TCP_CONGESTION> socket option).  The "
"items in the list are separated by white space and terminated by a newline "
"character.  The list is a subset of those listed in "
"I<tcp_available_congestion_control>.  The default value for this list is "
"\"reno\" plus the default setting of I<tcp_congestion_control>."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:304
#, no-wrap
msgid "I<tcp_autocorking> (Boolean; default: enabled; since Linux 3.14)"
msgstr ""

#.  commit f54b311142a92ea2e42598e347b84e1655caf8e3
#.  Text heavily based on Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:321
msgid ""
"If this option is enabled, the kernel tries to coalesce small writes (from "
"consecutive B<write>(2)  and B<sendmsg>(2)  calls) as much as possible, in "
"order to decrease the total number of sent packets.  Coalescing is done if "
"at least one prior packet for the flow is waiting in Qdisc queues or device "
"transmit queue.  Applications can still use the B<TCP_CORK> socket option to "
"obtain optimal behavior when they know how/when to uncork their sockets."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:321
#, no-wrap
msgid ""
"I<tcp_available_congestion_control> (String; read-only; since Linux 2.4.20)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:332
msgid ""
"Show a list of the congestion-control algorithms that are registered.  The "
"items in the list are separated by white space and terminated by a newline "
"character.  This list is a limiting set for the list in "
"I<tcp_allowed_congestion_control>.  More congestion-control algorithms may "
"be available as modules, but not loaded."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:332
#, no-wrap
msgid "I<tcp_app_win> (integer; default: 31; since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:337
msgid ""
"This variable defines how many bytes of the TCP window are reserved for "
"buffering overhead."
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:343
msgid ""
"A maximum of (I<window/2^tcp_app_win>, mss) bytes in the window are reserved "
"for the application buffer.  A value of 0 implies that no amount is reserved."
""
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:343
#, no-wrap
msgid "I<tcp_base_mss> (Integer; default: 512; since Linux 2.6.17)"
msgstr ""

#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:352
msgid ""
"The initial value of I<search_low> to be used by the packetization layer "
"Path MTU discovery (MTU probing).  If MTU probing is enabled, this is the "
"initial MSS used by the connection."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:352
#, no-wrap
msgid "I<tcp_bic> (Boolean; default: disabled; Linux 2.4.27/2.6.6 to 2.6.13)"
msgstr ""

#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:366
msgid ""
"Enable BIC TCP congestion control algorithm.  BIC-TCP is a sender-side only "
"change that ensures a linear RTT fairness under large windows while offering "
"both scalability and bounded TCP-friendliness.  The protocol combines two "
"schemes called additive increase and binary search increase.  When the "
"congestion window is large, additive increase with a large increment ensures "
"linear RTT fairness as well as good scalability.  Under small congestion "
"windows, binary search increase provides TCP friendliness."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:366
#, no-wrap
msgid ""
"I<tcp_bic_low_window> (integer; default: 14; Linux 2.4.27/2.6.6 to 2.6.13)"
msgstr ""

#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:373
msgid ""
"Set the threshold window (in packets) where BIC TCP starts to adjust the "
"congestion window.  Below this threshold BIC TCP behaves the same as the "
"default TCP Reno."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:373
#, no-wrap
msgid ""
"I<tcp_bic_fast_convergence> (Boolean; default: enabled; Linux 2.4.27/2.6.6 "
"to 2.6.13)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:377
msgid ""
"Force BIC TCP to more quickly respond to changes in congestion window.  "
"Allows two flows sharing the same connection to converge more rapidly."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:377
#, no-wrap
msgid ""
"I<tcp_congestion_control> (String; default: see text; since Linux 2.4.13)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:384
msgid ""
"Set the default congestion-control algorithm to be used for new connections. "
" The algorithm \"reno\" is always available, but additional choices may be "
"available depending on kernel configuration.  The default value for this "
"file is set as part of kernel configuration."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:384
#, no-wrap
msgid "I<tcp_dma_copybreak> (integer; default: 4096; since Linux 2.6.24)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:391
msgid ""
"Lower limit, in bytes, of the size of socket reads that will be offloaded to "
"a DMA copy engine, if one is present in the system and the kernel was "
"configured with the B<CONFIG_NET_DMA> option."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:391
#, no-wrap
msgid "I<tcp_dsack> (Boolean; default: enabled; since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:395
msgid "Enable RFC\\ 2883 TCP Duplicate SACK support."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:395
#, no-wrap
msgid "I<tcp_ecn> (Boolean; default: disabled; since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:402
msgid ""
"Enable RFC\\ 2884 Explicit Congestion Notification.  When enabled, "
"connectivity to some destinations could be affected due to older, "
"misbehaving routers along the path causing connections to be dropped."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:402
#, no-wrap
msgid "I<tcp_fack> (Boolean; default: enabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.92
#. type: Plain text
#: man-pages/man7/tcp.7:406
msgid "Enable TCP Forward Acknowledgement support."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:406
#, no-wrap
msgid "I<tcp_fin_timeout> (integer; default: 60; since Linux 2.2)"
msgstr ""

#.  Since 2.1.53
#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:416
msgid ""
"This specifies how many seconds to wait for a final FIN packet before the "
"socket is forcibly closed.  This is strictly a violation of the TCP "
"specification, but required to prevent denial-of-service attacks.  In Linux "
"2.2, the default value was 180."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:416
#, no-wrap
msgid "I<tcp_frto> (integer; default: 0; since Linux 2.4.21/2.6)"
msgstr ""

#.  Since 2.4.21/2.5.43
#. type: Plain text
#: man-pages/man7/tcp.7:425
msgid ""
"Enable F-RTO, an enhanced recovery algorithm for TCP retransmission timeouts "
"(RTOs).  It is particularly beneficial in wireless environments where packet "
"loss is typically due to random radio interference rather than intermediate "
"router congestion.  See RFC 4138 for more details."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:427
msgid "This file can have one of the following values:"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:430
msgid "Disabled."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:432
msgid "The basic version F-RTO algorithm is enabled."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:437
msgid ""
"Enable SACK-enhanced F-RTO if flow uses SACK.  The basic version can be used "
"also when SACK is in use though in that case scenario(s) exists where F-RTO "
"interacts badly with the packet counting of the SACK-enabled TCP flow."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:441
msgid ""
"Before Linux 2.6.22, this parameter was a Boolean value, supporting just "
"values 0 and 1 above."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:441
#, no-wrap
msgid "I<tcp_frto_response> (integer; default: 0; since Linux 2.6.22)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:448
msgid ""
"When F-RTO has detected that a TCP retransmission timeout was spurious (i.e, "
"the timeout would have been avoided had TCP set a longer retransmission "
"timeout), TCP has several options concerning what to do next.  Possible "
"values are:"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:456
msgid ""
"Rate halving based; a smooth and conservative response, results in halved "
"congestion window (I<cwnd>)  and slow-start threshold (I<ssthresh>)  after "
"one RTT."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:463
msgid ""
"Very conservative response; not recommended because even though being valid, "
"it interacts poorly with the rest of Linux TCP; halves I<cwnd> and "
"I<ssthresh> immediately."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:472
msgid ""
"Aggressive response; undoes congestion-control measures that are now known "
"to be unnecessary (ignoring the possibility of a lost retransmission that "
"would require TCP to be more cautious); I<cwnd> and I<ssthresh> are restored "
"to the values prior to timeout."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:473
#, no-wrap
msgid "I<tcp_keepalive_intvl> (integer; default: 75; since Linux 2.4)"
msgstr ""

#.  Since 2.3.18
#. type: Plain text
#: man-pages/man7/tcp.7:477
msgid "The number of seconds between TCP keep-alive probes."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:477
#, no-wrap
msgid "I<tcp_keepalive_probes> (integer; default: 9; since Linux 2.2)"
msgstr ""

#.  Since 2.1.43
#. type: Plain text
#: man-pages/man7/tcp.7:483
msgid ""
"The maximum number of TCP keep-alive probes to send before giving up and "
"killing the connection if no response is obtained from the other end."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:483
#, no-wrap
msgid "I<tcp_keepalive_time> (integer; default: 7200; since Linux 2.2)"
msgstr ""

#.  Since 2.1.43
#. type: Plain text
#: man-pages/man7/tcp.7:495
msgid ""
"The number of seconds a connection needs to be idle before TCP begins "
"sending out keep-alive probes.  Keep-alives are sent only when the "
"B<SO_KEEPALIVE> socket option is enabled.  The default value is 7200 seconds "
"(2 hours).  An idle connection is terminated after approximately an "
"additional 11 minutes (9 probes an interval of 75 seconds apart) when keep-"
"alive is enabled."
msgstr ""

#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:500
msgid ""
"Note that underlying connection tracking mechanisms and application timeouts "
"may be much shorter."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:500
#, no-wrap
msgid ""
"I<tcp_low_latency> (Boolean; default: disabled; since Linux 2.4.21/2.6)"
msgstr ""

#.  Since 2.4.21/2.5.60
#. type: Plain text
#: man-pages/man7/tcp.7:508
msgid ""
"If enabled, the TCP stack makes decisions that prefer lower latency as "
"opposed to higher throughput.  It this option is disabled, then higher "
"throughput is preferred.  An example of an application where this default "
"should be changed would be a Beowulf compute cluster."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:508
#, no-wrap
msgid "I<tcp_max_orphans> (integer; default: see below; since Linux 2.4)"
msgstr ""

#.  Since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:522
msgid ""
"The maximum number of orphaned (not attached to any user file handle) TCP "
"sockets allowed in the system.  When this number is exceeded, the orphaned "
"connection is reset and a warning is printed.  This limit exists only to "
"prevent simple denial-of-service attacks.  Lowering this limit is not "
"recommended.  Network conditions might require you to increase the number of "
"orphans allowed, but note that each orphan can eat up to ~64K of unswappable "
"memory.  The default initial value is set equal to the kernel parameter "
"NR_FILE.  This initial default is adjusted depending on the memory in the "
"system."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:522
#, no-wrap
msgid "I<tcp_max_syn_backlog> (integer; default: see below; since Linux 2.2)"
msgstr ""

#.  Since 2.1.53
#. type: Plain text
#: man-pages/man7/tcp.7:539
msgid ""
"The maximum number of queued connection requests which have still not "
"received an acknowledgement from the connecting client.  If this number is "
"exceeded, the kernel will begin dropping requests.  The default value of 256 "
"is increased to 1024 when the memory present in the system is adequate or "
"greater (E<gt>= 128Mb), and reduced to 128 for those systems with very low "
"memory (E<lt>= 32Mb).  It is recommended that if this needs to be increased "
"above 1024, TCP_SYNQ_HSIZE in I<include/net/tcp.h> be modified to keep "
"TCP_SYNQ_HSIZE*16E<lt>=tcp_max_syn_backlog, and the kernel be recompiled."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:539
#, no-wrap
msgid "I<tcp_max_tw_buckets> (integer; default: see below; since Linux 2.4)"
msgstr ""

#.  Since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:549
msgid ""
"The maximum number of sockets in TIME_WAIT state allowed in the system.  "
"This limit exists only to prevent simple denial-of-service attacks.  The "
"default value of NR_FILE*2 is adjusted depending on the memory in the system."
"  If this number is exceeded, the socket is closed and a warning is printed."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:549
#, no-wrap
msgid ""
"I<tcp_moderate_rcvbuf> (Boolean; default: enabled; since Linux 2.4.17/2.6.7)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:556
msgid ""
"If enabled, TCP performs receive buffer auto-tuning, attempting to "
"automatically size the buffer (no greater than I<tcp_rmem[2]>)  to match the "
"size required by the path for full throughput."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:556
#, no-wrap
msgid "I<tcp_mem> (since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:568
msgid ""
"This is a vector of 3 integers: [low, pressure, high].  These bounds, "
"measured in units of the system page size, are used by TCP to track its "
"memory usage.  The defaults are calculated at boot time from the amount of "
"available memory.  (TCP can only use I<low memory> for this, which is "
"limited to around 900 megabytes on 32-bit systems.  64-bit systems do not "
"suffer this limitation.)"
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:569
#, no-wrap
msgid "I<low>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:573
msgid ""
"TCP doesn't regulate its memory allocation when the number of pages it has "
"allocated globally is below this number."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:573
#, no-wrap
msgid "I<pressure>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:582
msgid ""
"When the amount of memory allocated by TCP exceeds this number of pages, TCP "
"moderates its memory consumption.  This memory pressure state is exited once "
"the number of pages allocated falls below the I<low> mark."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:582
#, no-wrap
msgid "I<high>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:586
msgid ""
"The maximum number of pages, globally, that TCP will allocate.  This value "
"overrides any other limits imposed by the kernel."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:587
#, no-wrap
msgid "I<tcp_mtu_probing> (integer; default: 0; since Linux 2.6.17)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:592
msgid ""
"This parameter controls TCP Packetization-Layer Path MTU Discovery.  The "
"following values may be assigned to the file:"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:595
msgid "Disabled"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:597
msgid "Disabled by default, enabled when an ICMP black hole detected"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:600
msgid "Always enabled, use initial MSS of I<tcp_base_mss>."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:601
#, no-wrap
msgid "I<tcp_no_metrics_save> (Boolean; default: disabled; since Linux 2.6.6)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:612
msgid ""
"By default, TCP saves various connection metrics in the route cache when the "
"connection closes, so that connections established in the near future can "
"use these to set initial conditions.  Usually, this increases overall "
"performance, but it may sometimes cause performance degradation.  If "
"I<tcp_no_metrics_save> is enabled, TCP will not cache metrics on closing "
"connections."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:612
#, no-wrap
msgid "I<tcp_orphan_retries> (integer; default: 8; since Linux 2.4)"
msgstr ""

#.  Since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:617
msgid ""
"The maximum number of attempts made to probe the other end of a connection "
"which has been closed by our end."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:617
#, no-wrap
msgid "I<tcp_reordering> (integer; default: 3; since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:626
msgid ""
"The maximum a packet can be reordered in a TCP packet stream without TCP "
"assuming packet loss and going into slow start.  It is not advisable to "
"change this number.  This is a packet reordering detection metric designed "
"to minimize unnecessary back off and retransmits provoked by reordering of "
"packets on a connection."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:626
#, no-wrap
msgid "I<tcp_retrans_collapse> (Boolean; default: enabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.96
#. type: Plain text
#: man-pages/man7/tcp.7:630
msgid "Try to send full-sized packets during retransmit."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:630
#, no-wrap
msgid "I<tcp_retries1> (integer; default: 3; since Linux 2.2)"
msgstr ""

#.  Since 2.1.43
#. type: Plain text
#: man-pages/man7/tcp.7:640
msgid ""
"The number of times TCP will attempt to retransmit a packet on an "
"established connection normally, without the extra effort of getting the "
"network layers involved.  Once we exceed this number of retransmits, we "
"first have the network layer update the route if possible before each new "
"retransmit.  The default is the RFC specified minimum of 3."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:640
#, no-wrap
msgid "I<tcp_retries2> (integer; default: 15; since Linux 2.2)"
msgstr ""

#.  Since 2.1.43
#. type: Plain text
#: man-pages/man7/tcp.7:650
msgid ""
"The maximum number of times a TCP packet is retransmitted in established "
"state before giving up.  The default value is 15, which corresponds to a "
"duration of approximately between 13 to 30 minutes, depending on the "
"retransmission timeout.  The RFC\\ 1122 specified minimum limit of 100 "
"seconds is typically deemed too short."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:650
#, no-wrap
msgid "I<tcp_rfc1337> (Boolean; default: disabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.90
#. type: Plain text
#: man-pages/man7/tcp.7:658
msgid ""
"Enable TCP behavior conformant with RFC\\ 1337.  When disabled, if a RST is "
"received in TIME_WAIT state, we close the socket immediately without waiting "
"for the end of the TIME_WAIT period."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:658
#, no-wrap
msgid "I<tcp_rmem> (since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:666
msgid ""
"This is a vector of 3 integers: [min, default, max].  These parameters are "
"used by TCP to regulate receive buffer sizes.  TCP dynamically adjusts the "
"size of the receive buffer from the defaults listed below, in the range of "
"these values, depending on memory available in the system."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:667 man-pages/man7/tcp.7:843
#, no-wrap
msgid "I<min>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:682
msgid ""
"minimum size of the receive buffer used by each TCP socket.  The default "
"value is the system page size.  (On Linux 2.4, the default value is 4K, "
"lowered to B<PAGE_SIZE> bytes in low-memory systems.)  This value is used to "
"ensure that in memory pressure mode, allocations below this size will still "
"succeed.  This is not used to bound the size of the receive buffer declared "
"using B<SO_RCVBUF> on a socket."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:682 man-pages/man7/tcp.7:853
#, no-wrap
msgid "I<default>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:696
msgid ""
"the default size of the receive buffer for a TCP socket.  This value "
"overwrites the initial default buffer size from the generic global I<net."
"core.rmem_default> defined for all protocols.  The default value is 87380 "
"bytes.  (On Linux 2.4, this will be lowered to 43689 in low-memory systems.) "
" If larger receive buffer sizes are desired, this value should be increased "
"(to affect all sockets).  To employ large TCP windows, the I<net.ipv4."
"tcp_window_scaling> must be enabled (default)."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:696 man-pages/man7/tcp.7:867
#, no-wrap
msgid "I<max>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:705
msgid ""
"the maximum size of the receive buffer used by each TCP socket.  This value "
"does not override the global I<net.core.rmem_max>.  This is not used to "
"limit the size of the receive buffer declared using B<SO_RCVBUF> on a socket."
"  The default value is calculated using the formula"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:707
#, no-wrap
msgid "    max(87380, min(4MB, I<tcp_mem>[1]*PAGE_SIZE/128))\n"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:710
msgid ""
"(On Linux 2.4, the default is 87380*2 bytes, lowered to 87380 in low-memory "
"systems)."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:711
#, no-wrap
msgid "I<tcp_sack> (Boolean; default: enabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.36
#. type: Plain text
#: man-pages/man7/tcp.7:715
msgid "Enable RFC\\ 2018 TCP Selective Acknowledgements."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:715
#, no-wrap
msgid ""
"I<tcp_slow_start_after_idle> (Boolean; default: enabled; since Linux 2.6.18)"
msgstr ""

#.  The following is from 2.6.28-rc4: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:723
msgid ""
"If enabled, provide RFC 2861 behavior and time out the congestion window "
"after an idle period.  An idle period is defined as the current RTO "
"(retransmission timeout).  If disabled, the congestion window will not be "
"timed out after an idle period."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:723
#, no-wrap
msgid "I<tcp_stdurg> (Boolean; default: disabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.44
#.  RFC 793 was ambiguous in its specification of the meaning of the
#.  urgent pointer.  RFC 1122 (and RFC 961) fixed on a particular
#.  resolution of this ambiguity (unfortunately the "wrong" one).
#. type: Plain text
#: man-pages/man7/tcp.7:737
msgid ""
"If this option is enabled, then use the RFC\\ 1122 interpretation of the TCP "
"urgent-pointer field.  According to this interpretation, the urgent pointer "
"points to the last byte of urgent data.  If this option is disabled, then "
"use the BSD-compatible interpretation of the urgent pointer: the urgent "
"pointer points to the first byte after the urgent data.  Enabling this "
"option may lead to interoperability problems."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:737
#, no-wrap
msgid "I<tcp_syn_retries> (integer; default: 5; since Linux 2.2)"
msgstr ""

#.  Since 2.1.38
#. type: Plain text
#: man-pages/man7/tcp.7:744
msgid ""
"The maximum number of times initial SYNs for an active TCP connection "
"attempt will be retransmitted.  This value should not be higher than 255.  "
"The default value is 5, which corresponds to approximately 180 seconds."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:744
#, no-wrap
msgid "I<tcp_synack_retries> (integer; default: 5; since Linux 2.2)"
msgstr ""

#.  Since 2.1.38
#. type: Plain text
#: man-pages/man7/tcp.7:750
msgid ""
"The maximum number of times a SYN/ACK segment for a passive TCP connection "
"will be retransmitted.  This number should not be higher than 255."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:750
#, no-wrap
msgid "I<tcp_syncookies> (Boolean; since Linux 2.2)"
msgstr ""

#.  Since 2.1.43
#. type: Plain text
#: man-pages/man7/tcp.7:770
msgid ""
"Enable TCP syncookies.  The kernel must be compiled with "
"B<CONFIG_SYN_COOKIES>.  Send out syncookies when the syn backlog queue of a "
"socket overflows.  The syncookies feature attempts to protect a socket from "
"a SYN flood attack.  This should be used as a last resort, if at all.  This "
"is a violation of the TCP protocol, and conflicts with other areas of TCP "
"such as TCP extensions.  It can cause problems for clients and relays.  It "
"is not recommended as a tuning mechanism for heavily loaded servers to help "
"with overloaded or misconfigured conditions.  For recommended alternatives "
"see I<tcp_max_syn_backlog>, I<tcp_synack_retries>, and "
"I<tcp_abort_on_overflow>."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:770
#, no-wrap
msgid "I<tcp_timestamps> (Boolean; default: enabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.36
#. type: Plain text
#: man-pages/man7/tcp.7:774
msgid "Enable RFC\\ 1323 TCP timestamps."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:774
#, no-wrap
msgid "I<tcp_tso_win_divisor> (integer; default: 3; since Linux 2.6.9)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:780
msgid ""
"This parameter controls what percentage of the congestion window can be "
"consumed by a single TCP Segmentation Offload (TSO) frame.  The setting of "
"this parameter is a tradeoff between burstiness and building larger TSO "
"frames."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:780
#, no-wrap
msgid "I<tcp_tw_recycle> (Boolean; default: disabled; since Linux 2.4)"
msgstr ""

#.  Since 2.3.15
#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:789
msgid ""
"Enable fast recycling of TIME_WAIT sockets.  Enabling this option is not "
"recommended since this causes problems when working with NAT (Network "
"Address Translation)."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:789
#, no-wrap
msgid "I<tcp_tw_reuse> (Boolean; default: disabled; since Linux 2.4.19/2.6)"
msgstr ""

#.  Since 2.4.19/2.5.43
#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:797
msgid ""
"Allow to reuse TIME_WAIT sockets for new connections when it is safe from "
"protocol viewpoint.  It should not be changed without advice/request of "
"technical experts."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:797
#, no-wrap
msgid ""
"I<tcp_vegas_cong_avoid> (Boolean; default: disabled; Linux 2.2 to 2.6.13)"
msgstr ""

#.  Since 2.1.8; removed in 2.6.13
#.  The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
#. type: Plain text
#: man-pages/man7/tcp.7:808
msgid ""
"Enable TCP Vegas congestion avoidance algorithm.  TCP Vegas is a sender-side "
"only change to TCP that anticipates the onset of congestion by estimating "
"the bandwidth.  TCP Vegas adjusts the sending rate by modifying the "
"congestion window.  TCP Vegas should provide less packet loss, but it is not "
"as aggressive as TCP Reno."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:808
#, no-wrap
msgid ""
"I<tcp_westwood> (Boolean; default: disabled; Linux 2.4.26/2.6.3 to 2.6.13)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:820
msgid ""
"Enable TCP Westwood+ congestion control algorithm.  TCP Westwood+ is a "
"sender-side only modification of the TCP Reno protocol stack that optimizes "
"the performance of TCP congestion control.  It is based on end-to-end "
"bandwidth estimation to set congestion window and slow start threshold after "
"a congestion episode.  Using this estimation, TCP Westwood+ adaptively sets "
"a slow start threshold and a congestion window which takes into account the "
"bandwidth used at the time congestion is experienced.  TCP Westwood+ "
"significantly increases fairness with respect to TCP Reno in wired networks "
"and throughput over wireless links."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:820
#, no-wrap
msgid "I<tcp_window_scaling> (Boolean; default: enabled; since Linux 2.2)"
msgstr ""

#.  Since 2.1.36
#. type: Plain text
#: man-pages/man7/tcp.7:834
msgid ""
"Enable RFC\\ 1323 TCP window scaling.  This feature allows the use of a "
"large window (E<gt> 64K) on a TCP connection, should the other end support "
"it.  Normally, the 16 bit window length field in the TCP header limits the "
"window size to less than 64K bytes.  If larger windows are desired, "
"applications can increase the size of their socket buffers and the window "
"scaling option will be employed.  If I<tcp_window_scaling> is disabled, TCP "
"will not negotiate the use of window scaling with the other end during "
"connection setup."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:834
#, no-wrap
msgid "I<tcp_wmem> (since Linux 2.4)"
msgstr ""

#.  Since 2.4.0-test7
#. type: Plain text
#: man-pages/man7/tcp.7:842
msgid ""
"This is a vector of 3 integers: [min, default, max].  These parameters are "
"used by TCP to regulate send buffer sizes.  TCP dynamically adjusts the size "
"of the send buffer from the default values listed below, in the range of "
"these values, depending on memory available."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:853
msgid ""
"Minimum size of the send buffer used by each TCP socket.  The default value "
"is the system page size.  (On Linux 2.4, the default value is 4K bytes.)  "
"This value is used to ensure that in memory pressure mode, allocations below "
"this size will still succeed.  This is not used to bound the size of the "
"send buffer declared using B<SO_SNDBUF> on a socket."
msgstr ""

#.  True in Linux 2.4 and 2.6
#. type: Plain text
#: man-pages/man7/tcp.7:867
msgid ""
"The default size of the send buffer for a TCP socket.  This value overwrites "
"the initial default buffer size from the generic global I</proc/sys/net/core/"
"wmem_default> defined for all protocols.  The default value is 16K bytes.  "
"If larger send buffer sizes are desired, this value should be increased (to "
"affect all sockets).  To employ large TCP windows, the I</proc/sys/net/ipv4/"
"tcp_window_scaling> must be set to a nonzero value (default)."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:876
msgid ""
"The maximum size of the send buffer used by each TCP socket.  This value "
"does not override the value in I</proc/sys/net/core/wmem_max>.  This is not "
"used to limit the size of the send buffer declared using B<SO_SNDBUF> on a "
"socket.  The default value is calculated using the formula"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:878
#, no-wrap
msgid "    max(65536, min(4MB, I<tcp_mem>[1]*PAGE_SIZE/128))\n"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:881
msgid ""
"(On Linux 2.4, the default value is 128K bytes, lowered 64K depending on low-"
"memory systems.)"
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:882
#, no-wrap
msgid ""
"I<tcp_workaround_signed_windows> (Boolean; default: disabled; since Linux 2."
"6.26)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:888
msgid ""
"If enabled, assume that no receipt of a window-scaling option means that the "
"remote TCP is broken and treats the window as a signed quantity.  If "
"disabled, assume that the remote TCP is not broken even if we do not receive "
"a window scaling option from it."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:888
#, no-wrap
msgid "Socket options"
msgstr ""

#.  or SOL_TCP on Linux
#. type: Plain text
#: man-pages/man7/tcp.7:906
msgid ""
"To set or get a TCP socket option, call B<getsockopt>(2)  to read or "
"B<setsockopt>(2)  to write the option with the option level argument set to "
"B<IPPROTO_TCP>.  Unless otherwise noted, I<optval> is a pointer to an I<int>."
"  In addition, most B<IPPROTO_IP> socket options are valid on TCP sockets.  "
"For more information see B<ip>(7)."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:906
#, no-wrap
msgid "B<TCP_CONGESTION> (since Linux 2.6.13)"
msgstr ""

#. 	    commit 5f8ef48d240963093451bcf83df89f1a1364f51d
#. 	    Author: Stephen Hemminger <shemminger@osdl.org>
#. type: Plain text
#: man-pages/man7/tcp.7:922
msgid ""
"The argument for this option is a string.  This option allows the caller to "
"set the TCP congestion control algorithm to be used, on a per-socket basis.  "
"Unprivileged processes are restricted to choosing one of the algorithms in "
"I<tcp_allowed_congestion_control> (described above).  Privileged processes "
"(B<CAP_NET_ADMIN>)  can choose from any of the available congestion-control "
"algorithms (see the description of I<tcp_available_congestion_control> "
"above)."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:922
#, no-wrap
msgid "B<TCP_CORK> (since Linux 2.2)"
msgstr ""

#.  precisely: since 2.1.127
#. type: Plain text
#: man-pages/man7/tcp.7:938
msgid ""
"If set, don't send out partial frames.  All queued partial frames are sent "
"when the option is cleared again.  This is useful for prepending headers "
"before calling B<sendfile>(2), or for throughput optimization.  As currently "
"implemented, there is a 200 millisecond ceiling on the time for which output "
"is corked by B<TCP_CORK>.  If this ceiling is reached, then queued data is "
"automatically transmitted.  This option can be combined with B<TCP_NODELAY> "
"only since Linux 2.5.71.  This option should not be used in code intended to "
"be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:938
#, no-wrap
msgid "B<TCP_DEFER_ACCEPT> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.38
#.  Useful references:
#.  http://www.techrepublic.com/article/take-advantage-of-tcp-ip-options-to-optimize-data-transmission/
#.  http://unix.stackexchange.com/questions/94104/real-world-use-of-tcp-defer-accept
#. type: Plain text
#: man-pages/man7/tcp.7:949
msgid ""
"Allow a listener to be awakened only when data arrives on the socket.  Takes "
"an integer value (seconds), this can bound the maximum number of attempts "
"TCP will make to complete the connection.  This option should not be used in "
"code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:949
#, no-wrap
msgid "B<TCP_INFO> (since Linux 2.4)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:955
msgid ""
"Used to collect information about this socket.  The kernel returns a "
"I<struct tcp_info> as defined in the file I</usr/include/linux/tcp.h>.  This "
"option should not be used in code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:955
#, no-wrap
msgid "B<TCP_KEEPCNT> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.18
#. type: Plain text
#: man-pages/man7/tcp.7:962
msgid ""
"The maximum number of keepalive probes TCP should send before dropping the "
"connection.  This option should not be used in code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:962
#, no-wrap
msgid "B<TCP_KEEPIDLE> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.18
#. type: Plain text
#: man-pages/man7/tcp.7:971
msgid ""
"The time (in seconds) the connection needs to remain idle before TCP starts "
"sending keepalive probes, if the socket option B<SO_KEEPALIVE> has been set "
"on this socket.  This option should not be used in code intended to be "
"portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:971
#, no-wrap
msgid "B<TCP_KEEPINTVL> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.18
#. type: Plain text
#: man-pages/man7/tcp.7:976
msgid ""
"The time (in seconds) between individual keepalive probes.  This option "
"should not be used in code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:976
#, no-wrap
msgid "B<TCP_LINGER2> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:988
msgid ""
"The lifetime of orphaned FIN_WAIT2 state sockets.  This option can be used "
"to override the system-wide setting in the file I</proc/sys/net/ipv4/"
"tcp_fin_timeout> for this socket.  This is not to be confused with the "
"B<socket>(7)  level option B<SO_LINGER>.  This option should not be used in "
"code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:988
#, no-wrap
msgid "B<TCP_MAXSEG>"
msgstr ""

#.  Present in Linux 1.0
#. type: Plain text
#: man-pages/man7/tcp.7:998
msgid ""
"The maximum segment size for outgoing TCP packets.  In Linux 2.2 and "
"earlier, and in Linux 2.6.28 and later, if this option is set before "
"connection establishment, it also changes the MSS value announced to the "
"other end in the initial packet.  Values greater than the (eventual) "
"interface MTU have no effect.  TCP will also impose its minimum and maximum "
"bounds over the value provided."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:998
#, no-wrap
msgid "B<TCP_NODELAY>"
msgstr ""

#.  Present in Linux 1.0
#. type: Plain text
#: man-pages/man7/tcp.7:1015
msgid ""
"If set, disable the Nagle algorithm.  This means that segments are always "
"sent as soon as possible, even if there is only a small amount of data.  "
"When not set, data is buffered until there is a sufficient amount to send "
"out, thereby avoiding the frequent sending of small packets, which results "
"in poor utilization of the network.  This option is overridden by "
"B<TCP_CORK>; however, setting this option forces an explicit flush of "
"pending output, even if B<TCP_CORK> is currently set."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1015
#, no-wrap
msgid "B<TCP_QUICKACK> (since Linux 2.4.4)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1030
msgid ""
"Enable quickack mode if set or disable quickack mode if cleared.  In "
"quickack mode, acks are sent immediately, rather than delayed if needed in "
"accordance to normal TCP operation.  This flag is not permanent, it only "
"enables a switch to or from quickack mode.  Subsequent operation of the TCP "
"protocol will once again enter/leave quickack mode depending on internal "
"protocol processing and factors such as delayed ack timeouts occurring and "
"data transfer.  This option should not be used in code intended to be "
"portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1030
#, no-wrap
msgid "B<TCP_SYNCNT> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.18
#. type: Plain text
#: man-pages/man7/tcp.7:1037
msgid ""
"Set the number of SYN retransmits that TCP should send before aborting the "
"attempt to connect.  It cannot exceed 255.  This option should not be used "
"in code intended to be portable."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1037
#, no-wrap
msgid "B<TCP_USER_TIMEOUT> (since Linux 2.6.37)"
msgstr ""

#. 	    commit dca43c75e7e545694a9dd6288553f55c53e2a3a3
#. 	    Author: Jerry Chu <hkchu@google.com>
#.  The following text taken nearly verbatim from Jerry Chu's (excellent)
#.  commit message.
#. type: Plain text
#: man-pages/man7/tcp.7:1055
msgid ""
"This option takes an I<unsigned int> as an argument.  When the value is "
"greater than 0, it specifies the maximum amount of time in milliseconds that "
"transmitted data may remain unacknowledged before TCP will forcibly close "
"the corresponding connection and return B<ETIMEDOUT> to the application.  If "
"the option value is specified as 0, TCP will to use the system default."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1062
msgid ""
"Increasing user timeouts allows a TCP connection to survive extended periods "
"without end-to-end connectivity.  Decreasing user timeouts allows "
"applications to \"fail fast\", if so desired.  Otherwise, failure may take "
"up to 20 minutes with the current system defaults in a normal WAN "
"environment."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1072
msgid ""
"This option can be set during any state of a TCP connection, but is only "
"effective during the synchronized states of a connection (ESTABLISHED, FIN-"
"WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, and LAST-ACK).  Moreover, when used "
"with the TCP keepalive (B<SO_KEEPALIVE>)  option, B<TCP_USER_TIMEOUT> will "
"override keepalive to determine when to close a connection due to keepalive "
"failure."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1075
msgid ""
"The option has no effect on when TCP retransmits a packet, nor when a "
"keepalive probe is sent."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1079
msgid ""
"This option, like many others, will be inherited by the socket returned by "
"B<accept>(2), if it was set on the listening socket."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1082
msgid ""
"Further details on the user timeout feature can be found in RFC\\ 793 and "
"RFC\\ 5482 (\"TCP User Timeout Option\")."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1082
#, no-wrap
msgid "B<TCP_WINDOW_CLAMP> (since Linux 2.4)"
msgstr ""

#.  Precisely: since 2.3.41
#. type: Plain text
#: man-pages/man7/tcp.7:1089
msgid ""
"Bound the size of the advertised window to this value.  The kernel imposes a "
"minimum size of SOCK_MIN_RCVBUF/2.  This option should not be used in code "
"intended to be portable."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:1089
#, no-wrap
msgid "Sockets API"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1098
msgid ""
"TCP provides limited support for out-of-band data, in the form of (a single "
"byte of) urgent data.  In Linux this means if the other end sends newer out-"
"of-band data the older urgent data is inserted as normal data into the "
"stream (even when B<SO_OOBINLINE> is not set).  This differs from BSD-based "
"stacks."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1105
msgid ""
"Linux uses the BSD compatible interpretation of the urgent pointer field by "
"default.  This violates RFC\\ 1122, but is required for interoperability "
"with other stacks.  It can be changed via I</proc/sys/net/ipv4/tcp_stdurg>."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1110
msgid ""
"It is possible to peek at out-of-band data using the B<recv>(2)  B<MSG_PEEK> "
"flag."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1126
msgid ""
"Since version 2.4, Linux supports the use of B<MSG_TRUNC> in the I<flags> "
"argument of B<recv>(2)  (and B<recvmsg>(2)).  This flag causes the received "
"bytes of data to be discarded, rather than passed back in a caller-supplied "
"buffer.  Since Linux 2.4.4, B<MSG_TRUNC> also has this effect when used in "
"conjunction with B<MSG_OOB> to receive out-of-band data."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:1126
#, no-wrap
msgid "Ioctls"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1132
msgid ""
"The following B<ioctl>(2)  calls return information in I<value>.  The "
"correct syntax is:"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1137
#, no-wrap
msgid ""
"B<int>I< value>B<;>\n"
"I<error>B< = ioctl(>I<tcp_socket>B<, >I<ioctl_type>B<, &>I<value>B<);>\n"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1142
msgid "I<ioctl_type> is one of the following:"
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1142
#, no-wrap
msgid "B<SIOCINQ>"
msgstr ""

#.  FIXME http://sources.redhat.com/bugzilla/show_bug.cgi?id=12002,
#.  filed 2010-09-10, may cause SIOCINQ to be defined in glibc headers
#. type: Plain text
#: man-pages/man7/tcp.7:1158
msgid ""
"Returns the amount of queued unread data in the receive buffer.  The socket "
"must not be in LISTEN state, otherwise an error (B<EINVAL>)  is returned.  "
"B<SIOCINQ> is defined in I<E<lt>linux/sockios.hE<gt>>.  Alternatively, you "
"can use the synonymous B<FIONREAD>, defined in I<E<lt>sys/ioctl.hE<gt>>."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1158
#, no-wrap
msgid "B<SIOCATMARK>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1163
msgid ""
"Returns true (i.e., I<value> is nonzero) if the inbound data stream is at "
"the urgent mark."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1179
msgid ""
"If the B<SO_OOBINLINE> socket option is set, and B<SIOCATMARK> returns true, "
"then the next read from the socket will return the urgent data.  If the "
"B<SO_OOBINLINE> socket option is not set, and B<SIOCATMARK> returns true, "
"then the next read from the socket will return the bytes following the "
"urgent data (to actually read the urgent data requires the B<recv(MSG_OOB)> "
"flag)."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1193
msgid ""
"Note that a read never reads across the urgent mark.  If an application is "
"informed of the presence of urgent data via B<select>(2)  (using the "
"I<exceptfds> argument) or through delivery of a B<SIGURG> signal, then it "
"can advance up to the mark using a loop which repeatedly tests B<SIOCATMARK> "
"and performs a read (requesting any number of bytes) as long as "
"B<SIOCATMARK> returns false."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1193
#, no-wrap
msgid "B<SIOCOUTQ>"
msgstr ""

#.  FIXME http://sources.redhat.com/bugzilla/show_bug.cgi?id=12002,
#.  filed 2010-09-10, may cause SIOCOUTQ to be defined in glibc headers
#. type: Plain text
#: man-pages/man7/tcp.7:1209
msgid ""
"Returns the amount of unsent data in the socket send queue.  The socket must "
"not be in LISTEN state, otherwise an error (B<EINVAL>)  is returned.  "
"B<SIOCOUTQ> is defined in I<E<lt>linux/sockios.hE<gt>>.  Alternatively, you "
"can use the synonymous B<TIOCOUTQ>, defined in I<E<lt>sys/ioctl.hE<gt>>."
msgstr ""

#. type: SS
#: man-pages/man7/tcp.7:1209
#, no-wrap
msgid "Error handling"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1214
msgid ""
"When a network error occurs, TCP tries to resend the packet.  If it doesn't "
"succeed after some time, either B<ETIMEDOUT> or the last received error on "
"this connection is reported."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1225
msgid ""
"Some applications require a quicker error notification.  This can be enabled "
"with the B<IPPROTO_IP> level B<IP_RECVERR> socket option.  When this option "
"is enabled, all incoming errors are immediately passed to the user program.  "
"Use this option with care \\(em it makes TCP less tolerant to routing "
"changes and other normal network conditions."
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:1225
#, no-wrap
msgid "ERRORS"
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1226
#, no-wrap
msgid "B<EAFNOTSUPPORT>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1232
msgid "Passed socket address type in I<sin_family> was not B<AF_INET>."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1232
#, no-wrap
msgid "B<EPIPE>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1236
msgid ""
"The other end closed the socket unexpectedly or a read is executed on a shut "
"down socket."
msgstr ""

#. type: TP
#: man-pages/man7/tcp.7:1236
#, no-wrap
msgid "B<ETIMEDOUT>"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1239
msgid "The other end didn't acknowledge retransmitted data after some time."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1243
msgid ""
"Any errors defined for B<ip>(7)  or the generic socket layer may also be "
"returned for TCP."
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:1243
#, no-wrap
msgid "VERSIONS"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1250
msgid ""
"Support for Explicit Congestion Notification, zero-copy B<sendfile>(2), "
"reordering support and some SACK extensions (DSACK) were introduced in 2.4.  "
"Support for forward acknowledgement (FACK), TIME_WAIT recycling, and per-"
"connection keepalive socket options were introduced in 2.3."
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:1250
#, no-wrap
msgid "BUGS"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1252
msgid "Not all errors are documented."
msgstr ""

#.  Only a single Linux kernel version is described
#.  Info for 2.2 was lost. Should be added again,
#.  or put into a separate page.
#.  .SH AUTHORS
#.  This man page was originally written by Andi Kleen.
#.  It was updated for 2.4 by Nivedita Singhvi with input from
#.  Alexey Kuznetsov's Documentation/networking/ip-sysctl.txt
#.  document.
#. type: Plain text
#: man-pages/man7/tcp.7:1262
msgid "IPv6 is not described."
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:1262
#, no-wrap
msgid "SEE ALSO"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1274
msgid ""
"B<accept>(2), B<bind>(2), B<connect>(2), B<getsockopt>(2), B<listen>(2), "
"B<recvmsg>(2), B<sendfile>(2), B<sendmsg>(2), B<socket>(2), B<ip>(7), "
"B<socket>(7)"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1276
msgid "RFC\\ 793 for the TCP specification."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1278
msgid ""
"RFC\\ 1122 for the TCP requirements and a description of the Nagle algorithm."
""
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1280
msgid "RFC\\ 1323 for TCP timestamp and window scaling options."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1282
msgid "RFC\\ 1337 for a description of TIME_WAIT assassination hazards."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1284
msgid "RFC\\ 3168 for a description of Explicit Congestion Notification."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1286
msgid "RFC\\ 2581 for TCP congestion control algorithms."
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1288
msgid "RFC\\ 2018 and RFC\\ 2883 for SACK and extensions to SACK."
msgstr ""

#. type: SH
#: man-pages/man7/tcp.7:1288
#, no-wrap
msgid "COLOPHON"
msgstr ""

#. type: Plain text
#: man-pages/man7/tcp.7:1296
msgid ""
"This page is part of release 3.70 of the Linux I<man-pages> project.  A "
"description of the project, information about reporting bugs, and the latest "
"version of this page, can be found at \\%http://www.kernel.org/doc/man-pages/"
"."
msgstr ""