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    SubjectRe: dst cache overflow
    >I have a busy webserver that stops responding to network traffic when
    >running for 7-10 days. First the server will gradually slow down and
    >then all network traffic will stop. The syslog is full of:
    >
    > dst cache overflow
    > NET: 173 messages suppressed.
    >
    >The machine is alive and well but to start network traffic I have to
    >reboot the machine.
    >Doing a 'netstat -t -n -o' says that there are 5364 connections in
    >LAST_ACK state, is this some kind of DOS or what?

    Don't know but the following might be used as a work-around:

    Set up a perl script to search for the ports used by the "LAST_ACK".

    Use this information to find the processes that hold these open, and
    use fuser -k to kill them.

    I used to have a news server that exhibited the same type of problem.
    My script limited the number of outstanding closes to 20-50. I sorted
    the list by port order, and killed all but the last 20. This kept the
    server up, and available. I think the web server will respawn processes
    as needed, but the leftover ones will be terminated and release the
    resources.

    It is a problem, but I don't know where, unless a timeout is set too
    large in the TCP/IP stack.
    -------------------------------------------------------------------------
    Jesse I Pollard, II
    Email: pollard@navo.hpc.mil

    Any opinions expressed are solely my own.

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