Re: IFF_POINTOPOINT and netmasks

Philip Blundell (
Fri, 23 May 1997 18:43:09 +0100 (BST)

On Fri, 23 May 1997, Miquel van Smoorenburg wrote:

> Why is this useful? Well, suppose I dial into my companies network. They
> have a class C, Now if I set the netmask to,
> a route would be added automatically to the remote system - that's useful,
> and that is what you would expect.

Ah, I think I see. What you want to do will only work if the remote
terminal server presents the same IP address on its dialin ports and on
its network connection. In the general case, they can be completely
different, and so the kernel is doing the right thing - when the
point-to-point link comes up all that you know for certain is that you can
reach the machine at the other end of it. If you happen to know that you
can also reach machines on its local network that way, you have to set up
a route by hand.

I'm not sure whether it would be good or not for the kernel to allow you
to do what you want.