From: gah@ugcs.caltech.edu   
      
   Jorgen Grahn  wrote:   
   > Assume I am on host A and have a long-lived TCP connection to host B   
   > (like a telnet or ssh session).  And then I bring my network interface   
   > down, and up again (e.g. using Unix ifconfig).  Or maybe it goes down   
   > and there is something automagical which brings up A's wireless link   
   > instead, with the same address.   
      
   > The question is this: should I expect my TCP connection to be alive   
   > after this?   
      
   > I think I have heard that Linux and the *BSDs make this work, but that   
   > Windows kills the TCP socket when the interface disappears from under   
   > it.  But that's a vague memory.  I can experiment with Linux, but not   
   > with all other IP stacks out there ...   
      
   I believe you can turn off the release of the IP address when   
   the interface goes down, at least on XP.  That means that you   
   have to IPCONFIG/RELEASE and/or IPCONFIG/RENEW when you actually   
   do change IP addresses or interfaces.   
      
   I used to do that so that I could carry my laptop from one room   
   to the next (on a wired net) and keep connections open.  I think   
   it is a registry entry.   
      
   That probably won't allow changes to different interfaces, even   
   with the same IP address, though.   
      
   -- glen   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)