>
> Date: Tue, 23 Mar 2010 23:54:47 +0000
> From: Matthew Brand <mtthwb...@googlemail.com>
> ...
> Can you randomise the port number?
> ...
>
As we say in America: Yes we can.
I start the server with a Windows command like this:
"C:\Program Files\j701\bin\J701Server.exe" JServerStartup.ijs
where "JServerStartup.ijs" in the J701 bin directory is something like this:
NB.* JServerStartup.ijs: load my usual environment in J7.01 and start
server.
NB. "C:\Program Files\J701\bin\J701Server.exe" JServerStartup.ijs
load 'DHMConfig.ijs'
jhs 1500
(where "DHMConfig.ijs" is my own startup script).
You could easily change "jhs 1500" to something like, e.g. " jhs 3#.3{.6!:0
'' "
to give a new port each day. The problem with making it completely random
is finding it from another machine when you want to. Note that the initial
"3" is arbitrary - you could agree on some other number with trusted
counterparties to allow them to derive your port for the day.
Based on the following information from Wikipedia, if you wanted to use the
"port per day" technique, you should probably do something like
jhs 49152+16383|3#.3{.6!:0 ''
to be within the "private" range 49152-65535 (16383=65535-49152).
[from Wikipedia:]
The Internet Assigned Numbers
Authority<http://en.wikipedia.org/wiki/Internet_Assigned_Numbers_Authority>(IANA)
is responsible for the global coordination of the DNS Root, IP
addressing, and other Internet protocol resources. This includes the
registration of commonly used port numbers for well-known Internet services.
The port numbers are divided into three ranges: the *well-known ports*, the
*registered ports*, and the *dynamic* or *private ports*. The *well-known
ports* are those from 0 through 1023. Examples include:
- *23*: Telnet <http://en.wikipedia.org/wiki/Telnet>
- *53*: Domain Name System<http://en.wikipedia.org/wiki/Domain_Name_System>
- *80*: World Wide Web
<http://en.wikipedia.org/wiki/World_Wide_Web>
HTTP<http://en.wikipedia.org/wiki/HTTP>
- *119*: Network News Transfer
Protocol<http://en.wikipedia.org/wiki/Network_News_Transfer_Protocol>
- *443*: HTTP over Transport Layer
Security<http://en.wikipedia.org/wiki/Transport_Layer_Security>
/Secure Sockets Layer <http://en.wikipedia.org/wiki/Secure_Sockets_Layer>
- *445*: microsoft-ds, Server Message
Block<http://en.wikipedia.org/wiki/Server_Message_Block>over TCP
The *registered ports* are those from 1024 through 49151. A list of
registered ports may be found on the IANA
Website.[1]<http://en.wikipedia.org/wiki/TCP_and_UDP_port#cite_note-IANA-0>The
dynamic or private ports are those from 49152 through 65535
--
Devon McCormick, CFA
^me^ at acm.
org is my
preferred e-mail
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