From: ndav1@cox.net   
      
   glen herrmannsfeldt wrote:   
   > 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   
      
   I believe that the registry setting is   
   \HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Para   
   eters\DisableDHCPMediaSense.   
   Setting it to 1 will mean that even if the connection is lost the   
   interface will maintain its address. This works even if the IP   
   configuration uses a static value instead of DHCP.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)