Linux : TCP queue size parameter

Posted on 2007-08-06
Last Modified: 2013-12-23
Hi experts,

 what is the linux kernel parameter that defines the TCP queue size? In solaris it is tcp_conn_req_max .

But I want to know what is that parameter in linux?
Question by:expertblr
    LVL 53

    Accepted Solution

    tcp_conn_req_max_q0 in Solaris (for connections doing SYN handshake) :


    is equivalent to tcp_max_syn_backlog in Linux :


    tcp_conn_req_max_q in Solaris (for established connections) :


    does not have a direct equivalent in Linux (at least, not that I know of). The number of allowed open connections depends on several factors, of which the most important are :

            1) the number of file descriptors allowed per process (configurable with ulimit)
            2) the amount of memory available (you can't open a new connection when there's no free memory)
            3) the CPU available (if the CPU is overloaded, new connections can't be accepted)

    To increase the number of file descriptors, you can follow the instructions at the bottom of this page :

    Maybe someone else has some better insights ...
    LVL 40

    Expert Comment


    Author Comment


    HI , I got the equivalent parameter in linux:


     Somaxconn default value is 128

    LVL 40

    Expert Comment



    How come my answer was not accepted and the provided links are talking about the same parameter?

    I do not see any point in accepting the other answer which is generic.


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