Wouldn't it just be easier to add a simple response required from the client? It doesn't have to be elaborate like a full login with passwords etc. But that would stop pretty much stop the scanning for listening ports. Maybe responding with the next letter in the alphabet. Silly, but should be effective.
On Tue, Mar 23, 2010 at 9:20 PM, Devon McCormick <[email protected]> wrote: > > > > Date: Tue, 23 Mar 2010 23:54:47 +0000 > > From: Matthew Brand <[email protected]> > > ... > > 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 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
