If you require a default route over a PPP link, choose one of the following options:
If both local and remote host addresses are statically assigned, you can use either of them as the default route.
If the remote host address is dynamically assigned, use the local host address as the default route.
If the local host address is dynamically assigned, use the remote host address as the default route.
If both the local and the remote host addresses are dynamically assigned, you cannot use a default route over a PPP link.