topic Re: ports allocation in Operating System - HP-UX

ports allocation

Alan D Johnson — Thu, 21 Feb 2002 20:54:57 GMT

Does any on know the order in which ports are allocated? is it lowest to highest, highest to lowest? Does it statr over at the lowest highest once the max has been reached?

Re: ports allocation

Patrick Wallek — Thu, 21 Feb 2002 21:08:57 GMT

What ports are you talking about? pty's?

I think with pty ports, it just looks for whatevever the next available one is. If pty/0 thru pty/10 are used and then pty/6 gets cleared, the next connection will use pty/6. I THINK!!!

Re: ports allocation

Ron Kinner — Thu, 21 Feb 2002 21:09:24 GMT

If you are talking about what port it uses to originate a TCP or UDP connection then it depends on the OS version. Early versions were very predictable and tended to stay within a narrow range (1K to 5K if I remember correctly). However, there were problems with hackers guessing the next number and doing nasty things to your system so later versions (at least from 11.0 on) use a very wide range of ports (around 5000 to 65K or so)and choose then in a random process. I think ndd offers an option to change the lowest number port tcp or udp can use.

Ron

Re: ports allocation

A. Clay Stephenson — Thu, 21 Feb 2002 21:13:37 GMT

Your question is not very clear but if you are referring to udp/tcp ports then then answer is that it depends. I assume that you are talking about requesting a port 0 so that the system selects an usused port otherwise your question makes no sense. Your best bet is to man 2 accept.

Re: ports allocation

Christopher E Chaves — Thu, 21 Feb 2002 21:14:10 GMT

Take a look at this document, it may shed some light on your question.

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=420cd34f146da595ea/screen=ckiDisplayDocument?docId=200000055253546