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Re: [Re: [Re: M$SQL cleanup incentives]]
From: Doug Barton <DougB () DougBarton net>
Date: Fri, 21 Feb 2003 20:24:31 -0800 (PST)


On Sat, 22 Feb 2003, E.B. Dreger wrote:

BB> Recent versions of un*x BIND will pick a random port above
BB> 1024 for udp conversations. It can and has picked 1434.

Standard socket(2) behavior.  BIND [hopefully] runs chown(2)ed,
so the source port number must be >= 1024.

At startup, named bind(2)'s a UDP port to send queries from, and get the
answers back on. In the absence of a query-source option that specifies
otherwise, this will be a random ephemeral port, however that's defined on
the system. TCP queries follow "standard" behavior, binding a random
ephemeral port for each query.

Pardon the pedantry, but since this is an often misundertood topic, I
thought it might help to lay out the facts.

HTH,

Doug

-- 

    "The last time France wanted more evidence, it rolled right
        through Paris with a German flag." - David Letterman


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