HP-UX Reference (11i v3 07/02) - 7 Device (Special) Files, 9 General Information, Index (vol 10)

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TCP(7P) TCP(7P)
timer has expired, TCP first compares the total time it has waited against the two
thresholds. If it has waited longer than the second threshold, TCP terminates the
connection. The default value for this option is the current value of the ndd tunable
tcp_ip_abort_cinterval
. See ndd(1M) online help for details on the
tcp_ip_abort_cinterval
default value.
TCP_KEEPCNT
(non-boolean option) When the SO_KEEPALIVE option is enabled, TCP probes a
connection that has been idle for some amount of time. If the remote system does not
respond to a keepalive probe, TCP retransmits the probe a certain number of times
before a connection is considered to be broken. The
TCP_KEEPCNT option can be
used to affect this value for a given socket, and specifies the maximum number of
keepalive probes to be sent. This option takes an
int value, with a range of 1 to
32767.
TCP_KEEPIDLE
(non-boolean option) When the SO_KEEPALIVE option is enabled, TCP probes a
connection that has been idle for some amount of time. The default value for this idle
period is 2 hours. The TCP_KEEPIDLE option can be used to affect this value for a
given socket, and specifies the number of seconds of idle time between keepalive
probes. This option takes an int value, with a range of 1 to 32767.
TCP_KEEPINIT
(non-boolean option) If a TCP connection cannot be established within some amount
of time, TCP will time out the connect attempt. The default value for this initial con-
nection establishment timeout is 75 seconds. The
TCP_KEEPINIT option can be
used to affect this initial timeout period for a given socket, and specifies the number of
seconds to wait before the connect attempt is timed out. For passive connections, the
TCP_KEEPINIT option value is inherited from the listening socket. This option
takes an int value, with a range of 1 to 32767.
TCP_KEEPINTVL
(non-boolean option) When the SO_KEEPALIVE option is enabled, TCP probes a
connection that has been idle for some amount of time. If the remote system does not
respond to a keepalive probe, TCP retransmits the probe after some amount of time.
The default value for this retransmit interval is 75 seconds. The TCP_KEEPINTVL
option can be used to affect this value for a given socket, and specifies the number of
seconds to wait before retransmitting a keepalive probe. This option takes an
int
value, with a range of 1 to 32767.
TCP_TSOPTENA
(boolean option) When this option is enabled, the sender places a timestamp in each
data segment. The receiver, if configured to accept them, sends these timestamps
back in ACK segments. This provides the sender with a mechanism with which to
measure round-trip time. TCP provides a Boolean option, TCP_TSOPTENA (from the
<netinet/tcp.h> header file) to enable or disable this option. This option takes
an
int value. When this option is enabled, the TCP_PAWS option is also enabled.
TCP_PAWS (boolean option) When the PAWS (Protect Against Wrapped Sequence numbers) option
is enabled, the receiver rejects any old duplicate segments that are received. This
option is used on synchronized TCP connections only. TCP provides a Boolean option,
TCP_PAWS (from the <netinet/tcp.h> header file) to enable or disable this
option. This option takes an int value. This option automatically turns the
TCP_TSOPTENA option on.
TCP_SACKENA
(boolean option) When the Selective Acknowledgment (SACK) option is enabled, the
data receiver can inform the sender about all segments that have arrived successfully.
In this way, the sender need retransmit only those segments that have actually been
lost. This option is useful in cases where multiple segments are dropped. TCP pro-
vides a Boolean option, TCP_SACKENA (from the <netinet/tcp.h> header file)
to enable or disable this option. This option takes an int value.
If TCP_NODELAY is set, the system sends small amounts of output immediately rather than gathering
them into a single packet after an acknowledgement is received. If TCP_NODELAY is not set, the system
sends data when it is presented, if there is no outstanding unacknowledged data. If there is outstanding
HP-UX 11i Version 3: February 2007 − 2 − Hewlett-Packard Company 205