[BC] Ports

[Cowboy]

On Thursday 29 May 2008 01:59 am, Jason R. wrote:

>     Big question -
>  Other than convenience for everybody, why use specific ports for any 
>  application - ?

 Simple answer, interoperable standards.

>     What I did was basically make sure the router would not respond to pings, 

 Generally a bad idea. ( yet too many Microsoft IT people insist on doing so )
 PING and PONG simply let you know the machine exists and is on-line, easily
 and conveniently.
 Shut off pong, and you have no easy way to know with certainty that you
 have a path.
 Traceroute and such all use ICMP ping.

>  and there were no ports open at all, other than to get in and out service. 
>  I watched the incoming data log for a while, then picked out some ports 
>  nobody seemed to try to find.  Like, why not use 8943 for something... or 
>  port 41100, or whatever the limit is on the router (and windouz)?

 If memory serves, the limit is 65536, but don't trust my memory.
 For something closed, ie: not intended for public consumption, there's
 nothing wrong with that, but don't use a "well known" port normally used
 by some standard application. You're asking for trouble if you do.

>     There seem to be huge numbers of folks in colleges in China, Venezuela, 
>  and Germany as well as Korea constants banging away at a handful of ports. 
>  I'm guessing I don't really want any of that traffic... so I did what I knew 
>  to do to not accept it, but the corporate folks wanted something "more 
>  conventional".
>  
>      Why?  What's the advantage?

 Remember how internet works.
 EVERYTHING is essentially some variant of telnet.
 Telnet port 80, you get web server. Telnet port 25, you get an SMTP server,
 etc.
 Imagine your browser does it's standard telnet port 80 GET, as all browsers do,
 but your web server is running on port 3216.
 What happens ?
 Nothing.

-- 
Cowboy