On Mon, Apr 21, 1997 at 01:12:12PM -0700, David Brownlee wrote:
> 
[...demand dial options...]
>
> 	What it wont do is demand dialup with dynamic IP addresses - you
> 	need at least a static local IP address.
> 
> 	If iij-ppp can manage dynamic local IP addresses that would be
> 	real interesting :)
> 
>                 David/abs               abs@anim.dreamworks.com

I use iij-ppp on a FreeBSD system.  The documentation
implies that you can only demand-dial to a static local IP
address, but a recent configuration change by my ISP forced
me to have a look at this, whereupon I discovered that
demand-dial to a dynamic IP address can be done.  I'll
describe the process here, in case it can be translated to
pppd.

In the /etc/ppp/ppp.conf file:

set ifaddr 0 1.1.1.1/0 0.0.0.0
add 0 0 1.1.1.1

The first line says something like:

"ifconfig tun0 inet 0.0.0.0 1.1.1.1 netmask 0.0.0.0"

but the "/0" says that the ppp IPCP handshake should insist
on NONE of the bits in the remote address.

The second line is the same as saying:
"route add default 1.1.1.1" at the command line

The /etc/ppp/ppp.linkup script (which is run once the connection is
made) says:

MYADDR:
add 0 0 HISADDR

which is sort of a generic, match all case that says

"route add default <actual destination address>"

I've experienced no ill effects since changing to this
arrangement, but if anyone has any strong objections to any
of the steps listed above I'll happily have another
re-think.

-- 
Andrew

"The steady state of disks is full."
				-- Ken Thompson