RE: [rtl] Off Topic - Ethernet releasing port addresses

[GIFFORD KEVIN K <gifford@rintintin.colorado.edu>]

On Mon, 30 Jul 2001, Estabridis, Janet P wrote:

>  DOES ANYONE HAVE ANY COMMENTS ON THIS ?
>
> My problem is that sometimes when I know I have closed the code out and
> I restart it I get the message
>
> Unable to establish a port Connection:  Address already in use.

Hi Janet -

    Is the message "Address already in use" or is it "Port already
in use"?  This seems like it may be a half-open TCP connection in
which one side has closed the connection but the other side of the
TCP connection still has the connection open.  There are a couple of
ways to check for this condition via (1) implement TCP keep-alive timer,
or (2) in user space - check for write errors to the TCP connection
returned by the Linux kernel, then take appropriate action.

    As a suggestion, I heartily recommend "TCP/IP Illustrated", Volumes
1 and 2 by W. Richard Stevens.

Hope this helps.

Kevin Gifford