• Wei Yongjun's avatar
    [TCP]: SNMPv2 tcpAttemptFails counter error · 3687b1dc
    Wei Yongjun authored
    Refer to RFC2012, tcpAttemptFails is defined as following:
      tcpAttemptFails OBJECT-TYPE
          SYNTAX      Counter32
          MAX-ACCESS  read-only
          STATUS      current
          DESCRIPTION
                  "The number of times TCP connections have made a direct
                  transition to the CLOSED state from either the SYN-SENT
                  state or the SYN-RCVD state, plus the number of times TCP
                  connections have made a direct transition to the LISTEN
                  state from the SYN-RCVD state."
          ::= { tcp 7 }
    
    When I lookup into RFC793, I found that the state change should occured
    under following condition:
      1. SYN-SENT -> CLOSED
         a) Received ACK,RST segment when SYN-SENT state.
    
      2. SYN-RCVD -> CLOSED
         b) Received SYN segment when SYN-RCVD state(came from LISTEN).
         c) Received RST segment when SYN-RCVD state(came from SYN-SENT).
         d) Received SYN segment when SYN-RCVD state(came from SYN-SENT).
    
      3. SYN-RCVD -> LISTEN
         e) Received RST segment when SYN-RCVD state(came from LISTEN).
    
    In my test, those direct state transition can not be counted to
    tcpAttemptFails.
    Signed-off-by: default avatarWei Yongjun <yjwei@nanjing-fnst.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    3687b1dc
tcp_minisocks.c 21 KB