• Alex Bergmann's avatar
    tcp: Increase timeout for SYN segments · 6c9ff979
    Alex Bergmann authored
    Commit 9ad7c049 ("tcp: RFC2988bis + taking RTT sample from 3WHS for
    the passive open side") changed the initRTO from 3secs to 1sec in
    accordance to RFC6298 (former RFC2988bis). This reduced the time till
    the last SYN retransmission packet gets sent from 93secs to 31secs.
    
    RFC1122 is stating that the retransmission should be done for at least 3
    minutes, but this seems to be quite high.
    
      "However, the values of R1 and R2 may be different for SYN
      and data segments.  In particular, R2 for a SYN segment MUST
      be set large enough to provide retransmission of the segment
      for at least 3 minutes.  The application can close the
      connection (i.e., give up on the open attempt) sooner, of
      course."
    
    This patch increases the value of TCP_SYN_RETRIES to the value of 6,
    providing a retransmission window of 63secs.
    
    The comments for SYN and SYNACK retries have also been updated to
    describe the current settings. The same goes for the documentation file
    "Documentation/networking/ip-sysctl.txt".
    Signed-off-by: default avatarAlexander Bergmann <alex@linlab.net>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6c9ff979
tcp.h 50.8 KB