Subject: [MOBILE-IP] Mobile IP Routing Implementation Issue

From: Gavin Button <[email-masked]>
Date: Fri, 13 Oct 2000 12:14:23 +0100

Hi All,

I am researching and implementing MobileIP as defined in RFC2002, October
1996 and have a question.

My configuration within a private network is as follows:
Mobile Host: IP address 100.100.101.239
Home Agent: IP address 100.100.101.233
Foreign Agent: IP Address 10.0.0.2
(all subnet masks are 255.255.255.0)

The Mobile Host visits the Foreign Agent network and registers the Care of
Address (10.0.0.2) with the Home Agent. Once registration has completed I
ping the Mobile Host from a machine on its Home Network (100.100.100.207).
The ping request reaches the Mobile Host succesfully, at which point the
TCP/IP stack attempts a broadcast ARP Request to determine the MAC address
of 100.100.101.207, which it believes to be on the same network, this fails
so the ping reply is never generated.

The section in RFC 2002 on Mobile Host Datagram Routing (4.2.1) states that
a default router should be selected for the foreign network. If I do this
and set the deafult router to be 10.0.0.1 (router between the two networks)
then it still does generates an ARP request for 100.100.101.207. I believe
this is because the TCP/IP stack doesnt recognise the router, 10.0.0.1, as
being on the same network as its IP Address, 100.100.101.239, so does not
consider it for sending the ping reply to.

Can anyone explain what I might be doing wrong?

Thanks in Advance,

Gavin Button

---

From: Gavin Button <[email-masked]>
Date: Fri, 13 Oct 2000 13:10:44 +0100

%
% Hi All,
%
% I am researching and implementing MobileIP as defined in RFC2002, October
% 1996 and have a question.
%
% My configuration within a private network is as follows:
% Mobile Host: IP address 100.100.101.239
% Home Agent: IP address 100.100.101.233
% Foreign Agent: IP Address 10.0.0.2
% (all subnet masks are 255.255.255.0)
%
% Can anyone explain what I might be doing wrong?
%
% Gavin Button

        First off, network 100.0.0.0/8 is -NOT- a private network
        number.

Ok, maybe the use of 'private network' was not quite correct. What I meant
is that is a local network I have setup up for testing purposes only, which
is not connected to the internet.

Gavin