On Sat, 13 Jun 2009 12:25:13 -0600 Jon <scr...@nonvocalscream.com> wrote: >Thank you for that thoughtful explanation. > >This was probably explained somewhere during the thread, I apologize >if I missed it... > >Could you clarify the definition of "bogus traffic" for me. > Well, the definition I've been using probably isn't terribly rigorous, at least in the sense that there are quite a few justifiable exceptions to it. But basically it goes like this. IANA maintains a list of port numbers that are reserved for certain services' use. A lot of software is written to use the reserved port numbers as the default port numbers for communications supporting the services for which the numbers are reserved, although some implementations of the relevant clients and servers allow direction that some alternative port numbers be used instead, a feature fairly essential for testing in many situations. However, when the use of a reserved port number is hijacked for some other service than the one for which it is reserved, the new usage constitutes "bogus traffic" in most cases. tor itself provides an example of two exceptions (one each for ORPort and DirPort) justified by the necessity of evading the attempts by certain parties to block access to tor's services. Thus the plea in the tor documentation to get some tor nodes to use ports 80 and 443 for ORPort and DirPort seems a justified exception to the general rule. (I am a bit uncomfortable with the expectation that using port 80 for ORPort can evade intrusion and/or blocking by the likes of China's Great Firewall because all the firewall would need to do to decide whether to block it would be to see whether a connection were encrypted. Connections coming into an ORPort are supposed to be encrypted, but http connections are not. The same thing in reverse would appear to apply to looking at port 443 connections because https is supposed to be encrypted, whereas DirPort connections are not.) Note that ports 9001 and 9030, the defaults for ORPort and DirPort, are not reserved ports, according to IANA's list, so anyone is free to use them for any other purpose. Now, another person on this list has argued that the RFC's should be ignored and that IANA should be ignored. I remain unconvinced that doing either would be a good idea. Having a set of standard port numbers at which one may expect to access standard services is valuable, and much of what we have all come to expect from networking and the Internet would be effectively hidden from our access if these standards were not followed by most system and/or network adminstrators. This concept is not different in principle from having 802.11[abgn] channels assigned to certain frequency bands where we can expect to find access points. If people routinely adjusted software-tunable transmitters and receivers in wireless interfaces to other parts of the EM spectrum, most people would soon stop wasting their time trying to connect to attach points. Conversely, if ham radio operators routinely adjusted their equipment to operate in the frequency bands reserved for 802.11[abgn] wireless networks, there would also be a lot of unhappy computer users.
Scott Bennett, Comm. ASMELG, CFIAG ********************************************************************** * Internet: bennett at cs.niu.edu * *--------------------------------------------------------------------* * "A well regulated and disciplined militia, is at all times a good * * objection to the introduction of that bane of all free governments * * -- a standing army." * * -- Gov. John Hancock, New York Journal, 28 January 1790 * **********************************************************************