From: lacos@caesar.elte.hu   
      
   On Thu, 16 Sep 2010, Jorgen Grahn wrote:   
      
   > On Thu, 2010-09-16, Elton wrote:   
   >>> Sure, but that blocks a lot of traffic that may well be requested by   
   >>> something you did on your end. It's comparable to ISP's that block   
   >>> "spoofed traffic", but what they mean by "spoofed" is not that the   
   >>> origin is invalid or incorrect but simply that it's not the one *they*   
   >>> assigned. Shoot at the wall, towards the target, and call whatever you   
   >>> can hit the bullseye.   
   >>   
   >> So TCP SYNs can also be the result of a request by me, and a new   
   >> connection starts to create as a result of this request.   
   >   
   > Yes!   
   >   
   >> But then how do ISPs find out if it was a packet sent to me as a   
   >> result of a request (solicited packet), or if they are TCP SYN packets   
   >> sent to my computer without I requesting it (unsolicited packets) ?   
   >   
   > Well, like Morten writes elsewhere in the thread, they can't. Unless   
   > they get to define the meaning of "solicited" on your behalf.   
   >   
   > (By the way, I have never heard of ISPs that do crazy stuff like   
   > that.)   
      
   I believe my ISP blocks the ports nmbd and smbd would normally bind, so   
   that domestic subscribers running Windows can't accidentally share their   
   folders and printers. I also hear that for domestic subscribers, 25/tcp is   
   blocked, so that they can't run their own SMTP servers. (The reasoning   
   goes supposedly like "if you want such functionality, buy a business   
   package".)   
      
   lacos   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)