Re: Ephemeral ports

In article <f7c30ddb-5f3e-4cc2-8419->,
Karthik Balaguru <> writes:
> Hi,
> While looking for some valid port configurations,
> i came across that in Solaris 2.2 by default the
> ephemeral ports for TCP and UDP start at 32768.
> Just eager to know the reason of why does it
> start at 32768 (2 to the power of 15) ?
> And i wonder why does it not follow the IANA range ?
>
> Interestingly, many linux kernels also use the
> same and why do not they stick towards IANA range ?
>
> BSD and Windows stick towards 1024 to 4999
> and 1025 to 5000 respectively, while Vista and
> FreeBSD stick towards IANA range !
>
> Any ideas ?

Solaris systems are often used for servers with hundreds of thousands
of network connections. Hence it is also often used for testing these
servers supporting a million or so network connections. By doubling
the number of ephemeral ports available, you can create twice as many
connections from a testing system to the server per IP address.
Solaris allows the tcp_smallest_anon_port (and tcp_largest_anon_port)
to be changed whilst system is running, and on testing systems, the
tcp_smallest_anon_port is sometimes lowered to make even more anon/
ephemeral ports available. Same can be done for UDP.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]