Re: Devices with dynamic IP numbers can be annoying.

Alan Cox (alan@lxorguk.ukuu.org.uk)
Tue, 23 Sep 1997 19:58:17 +0100 (BST)


> or FTP. If these programs are still running when the connection goes down,
> before exitting, they will transmit 1 byte to the remote hosts recently
> visited, using the stale IP number... and the socket goes into the FIN_WAIT1
> state for 15 minutes before timeout.

They try to close the socket. This is the right thing to do. We can't reuse
that stuck socket.

> Even if a new PPP route is established, the "local" address of the link will
> change, and the transmitted packet has an outdated return IP address... Some
> other host will receive the ACK your host requested.

Yep. There isnt anything to do about that.

> 1. In the kernel, when creating a socket, make sure that the "local" IP number
> is listed in the network devices. If not, have the bind() or connect()
> call fail. This would prevent *new* sockets from using stale (or fake!)
> IP numbers.

It already does this ( you get "Address not available")

Alan