help setting up Nextel wireless modem

I'm trying to set this modem up under Linux. I have a CD for
Windows to help with the installation (there's a gui)
and have printed out the docs which don't seem
to have anything to do with networking as I know it.
The techical help at Nextel is hopeless.

The modem picks up a signal at 2.4GHz which is being
sent over power lines (AFAIK at least, the signal is BPL,
broadband over powerline). The modem has an antenna
and is powered by a 120V wallwart (if the signal is
coming over the powerline, I don't know why it isn't
coming in through the wallwart).

You connect your linux box to the modem by ethernet.
Presumably the modem looks like a bridge.

I'm trying to setup the connection from the linuxbox to
the modem.

I connect the two boxes by ethernet, and dhcp on the
linux box where I get the following IPs (from the dhcp
leases file). The link lights on the ethernet connectors
light up on connecting the ethernet cable and the entries
in the leases file expire and are renewed every 60secs,
so I assume I have the ethernet link layer working.

IP of linux box 65.76.244.243/32
IP of router 172.29.251.133 (at ISP?)
IPs for two nameservers 172.29.251.x and y
IP of dhcp server 172.30.30.128 (IP of modem?)

I assume the IP for the dhcp server is the IP of the ethernet
device inside the modem. I assume the IP of the router is
the IP that should be at the other end of my P-t-P connection

What I think I need to do is something like

# ifconfig eth1 my_IP pointopoint router_IP

however the pointopoint isn't accepted (I just get
an normal eth1 with an IP). Adding a /32 netmask
and broadcast to the above command doesn't get me
P-t-P.

I can't figure out how to set POINTOPOINT with iproute2,
although the docs say that `ip link eth1 show`
will show the POINTOPOINT if it's there.

I've only ever seen P-t-P with ppp0 and not with
regular NICs, so I looked in /usr/sbin/ppp-go etc
to see where/how a P-t-P connection is setup. I couldn't
find it.

Does anyone know what I'm supposed to do here or how
to setup P-t-P over a NIC?

Thanks Joe
--
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
generator at http://www.wm7d.net/azproj.shtml
Homepage http://www.austintek.com/ It's GNU/Linux!