Subject: [mobile-ip] Moible IP and UDP tunneling problem

From: Peng Gao <[email-masked]>
Date: Fri, 26 Jul 2002 10:44:14 +0200

I am a student at Technical University of Munich.  I am doing my thesis
named Mobile IP and NAPT Interaction.  I plan to set up a new UDP data
tunneling to go through the NAPT by Netfilter, but I meet a lot of 
problems now.

Firstly, could you please give me some advice about how to distinguish 
Registration
Reply from UDP data tunneling at Foreign Agent?  Since both are UDP
datagram, and have same IP Address and UDP Port.    I know maybe I can
check the payload of the datagram, but I am not sure which part I should
check.

Secondly,  I plan to write  a module for Home Agent, and the module stay 
outside of the normal Home Agent process.  That means before the HA 
process send out the IP-in-IP data tunneling, my module works and 
inserts the UDP header and make it to UDP data tunneling.  Now, I can 
not insert the UDP header correctly.  So, if you already did the same 
thing.  Could you please show me some source code about how to insert 
the UDP header?
 
I will really appreciate your helping me!

Best wishes!

Peng Gao

---

From: "Henrik Levkowetz" <[email-masked]>
Date: Fri, 26 Jul 2002 12:01:43 +0200

Peng Gao,

	This sounds as if you are trying to do basically the same thing
which is described in the Mobile IP NAT traversal draft, but without
having read that particular document. Would you have a look at 

 http://www.ietf.org/internet-drafts/draft-ietf-mobileip-nat-traversal-05.txt

and see it that answers your questions?

	Regards,

		Henrik