DEC Unix 3.2c UDP port reallocation scheme not working??????

From: <marchany_at_vtserf.cc.vt.edu>
Date: Wed, 24 Jan 96 13:53:35 -0500

    What is the allocation algorithm for UDP socket port numbers
    under DEC Unix 3.2c? What is the range of valid UDP port numbers? I have a
    number of UDP client processes that bind to an INADDR_ANY port, do some
    transactions, and close the port. I'm seeing a situation where UDP ports
    are reallocated in a short timeframe, causing one client to get a second
    clients packets. For example,
 
            Client A binds to any port and gets 1057
        Client A sends a request to a server, times out, and retries, times
                out, retries, and gives up. He closes his socket.
        A short time later, client B binds to any port, gets 1057, and
                receives the packets sent by the server intended for client A.

    I solved the problem by passing some information in the UDP packet that
    allows the client to ignore packets not meant for him. However, I
    never encountered this problem running the same code on another Unix
    system; so I'm curious how DEC Unix decides which port it will assign
    next when INADDR_ANY is used in bind().
    
As usual, our call to the DEC support center yielded nothing.

        -Thanks
        Randy Marchany
        VA Tech Computing Center
        Blacksburg, VA 24060

INTERNET: randy.marchany_at_vt.edu

        

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Received on Wed Jan 24 1996 - 20:38:29 NZDT

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