[lwip-devel] [patch #5779] Tunning TCP KeepAlives values

[Frédéric Bernon]

Follow-up Comment #8, patch #5779 (project lwip):

I also study setsockopt options. Can you tell me if these descriptions are
good for you (or can you give me more informations)?

http://www4.iastate.edu/cgi-bin/man2html?tcp(7)

TCP_KEEPIDLE
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 N (where N is
tcp_keepidle divided by PR_SLOWHZ). For more information on tcp_keepidle see
the information on the inet subsystem configuration attributes in the System
Configuration and Tuning guide. PR_SLOWHZ is defined in the <sys/protosw.h>
header file.

TCP_KEEPINTVL
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 N (where N is tcp_keepintvl divided
by PR_SLOWHZ). For more information on tcp_keepintvl see the information on
the inet subsystem configuration attributes in the System Configuration and
Tuning guide. PR_SLOWHZ is defined in the <sys/protosw.h> header file.

TCP_KEEPCNT
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 default value for this keepalive
probe retransmit limit is 8. 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
tcp_keepcnt. For more information on tcp_keepcnt see the information on the
inet subsystem configuration attributes in the System Configuration and
Tuning guide.


    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/patch/?5779>

_______________________________________________
  Message posté via/par Savannah
  http://savannah.nongnu.org/