PPP DHCP client

[Glenn Satchell]

>Subject: PPP DHCP client
>Date: Tue, 27 Feb 2007 18:52:39 -0500
>From: "Gonzalez, Pedro - ACD " <Pedro.Gonzalez at itt.com>
>To: <dhcp-users at isc.org>
>
>Hi,
>I need to run DHCP over a PPP interface.
>The PPP interface between my 2 devices is up and running, and my
>application calls for the client (Linux) to be assigned an IP address
>via DHCP.
>
>I tried to evoke the dhcp client over the ppp interface as shown below,
>I see that the system is sending DHCP discover messages, however they
>are not making to the wire since I don't see them on the Sniffer.
>
>The following is the output of launching the "dhclient" command in
>Linux...
>
>[root at icb ppp]# dhclient ppp0
>
>Internet Systems Consortium DHCP Client V3.0.2-RedHat
>Copyright 2004 Internet Systems Consortium.
>All rights reserved.
>For info, please visit http://www.isc.org/products/DHCP
>
>ppp0: unknown hardware address type 512
>ppp0: unknown hardware address type 512
>Listening on LPF/ppp0/
>Sending on   LPF/ppp0/
>Sending on   Socket/fallback
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 5
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 6
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 15
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 9
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 14
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 8
>DHCPDISCOVER on ppp0 to 255.255.255.255 port 67 interval 4
>No DHCPOFFERS received.
>No working leases in persistent database - sleeping.
>
>As per output above, it looks like PPP0 is not being recognized, and the
>program "dhclient" is listening and sending the messages on /LPF/ppp0
>instead of PPP0.  Can I fix this problem by modifying any of
>configuration files on my system, and if yes, which files do I need to
>modify?
>
>
>The following is my system's software build...
>
>[root at icb ppp]# uname -a
>Linux icb 2.6.11-1.1369_FC4 #1 Thu Jun 2 22:55:56 EDT 2005 i686 i686
>i386 GNU/Linux
>
>
>Thanks,
>
>-Pedro-

Sorry won't work. dhcp only knows about specific types of interfaces
that support the features it needs, and PPP is not one of those.

PPP uses it's own link negotiation protocol to assign IP addresses and
similar information, so yuou shouldn't need dhcp to get a PPP address.
If you're using some sort of access server at the other end of the PPP
link then that canusually be configured to act as a proxy and obtain
address from a dhcp server and then supply them to the remote end of
the PPP link. That's what thinks like Windows RAS and Cisco Access
Servers do.

regards,
-glenn