Messaging Gateway

 View Only
  • 1.  Connection reset by peer

    Posted May 19, 2010 07:48 PM

    Hi,

    I'm new in SBG. A problem started 1 month ago that when a remote MTA delivers messages larger than 3M to SBG, it always failed with the error message "Error 54 Connection reset by peer" from remote MTA's logs. However, it's working well when the remote MTA send to SBG with a message less than 3M.

    Also, the remote MTA's administrator said he saw the idle timeout for SMTP session seemed just 15 seconds. I mean the smtp session will be closed  when the idle time execeed about  15s after a smtp connection established successfully (They tried this via telnet to port 25).

    I'm not sure if there is any inappropriate configuration in Scanner settings.

    Any suggestions appreciated.

    Thanks,

    -Lao



  • 2.  RE: Connection reset by peer

    Posted May 20, 2010 11:33 AM

    Add something: Session Timout is set to 30s for inbound connection. Does this cause connection reset? 



  • 3.  RE: Connection reset by peer

    Posted May 21, 2010 09:28 AM

    Laowu,


         The session timeout value is the amount of time that the MTA will wait for a command to be sent from the remote MTA.  If for some reason during a connection the remote MTA fails to respond within 30 seconds the appliance WILL close the connection.  If you are able to reliably reproduce the issue I would suggest monitoring the packet exchange and see if there is a delay in the transmission.  If you use mysupport or call into support to open a ticket a tech can give you the directions for running the TCPDump on the appliance.  I prefer to do it on the firewall but the choice is yours.


  • 4.  RE: Connection reset by peer

    Posted May 21, 2010 07:01 PM

    Thanks John.
    I asked remote MTA to do a tcpdump. They found that SBG would aborted the smtp session while transferring in process if the sesstion time exceeds 30s(our SBG session timeout is 30s). We tried  to change session timeout to 120s, then aborted session at the timing of 120s while transferring in process.

    In user guide 8.0, it says something about session time:
    This setting controls how long the MTA waits for a request or response from the connecting MTA. If this limit is exceeded, the appliance will drop the connection.

    My understanding was that the session timeout is about idle time(it says 'waitting'). However, it seems about sesseion time instead of idle time. Am I  correct?

    Thanks,

    -Laowu


  • 5.  RE: Connection reset by peer

    Posted May 24, 2010 09:18 AM

    Yes,  the idle time should be between commands (helo, mail from, etc).  I had a similar problem with an internal application where the application was starting the converstation with helo,  but acting like it had done an ehlo and was doing pipelining - issuing mulitple commands instead of waiting for an MTA response.  SBG may be thinking that the DATA portion of the traffic is part of the initial pre-data setup.  Check for SBG responses to the initial commands.