Subject: [mobile-ip] tunnel back to home agent

From: Sashikiran Rachakonda <[email-masked]>
Date: Fri, 28 Jun 2002 08:37:48 -0700 (PDT)

Kernel Version : Linux 2.4

Prob Descrp    : When a mobile node goes into a foreign network, it
		 acts as a dhcp client and gets a new address. I bind this 
		 new address to eth0 and the mobile node's home address 
		 to a tunnel device,the remote end of the tunnel being 
                 the address of the home agent. The idea is to tunnel  
		 back to home from mobile node. That way the packets that 
		 leave the mobile node first reach the home agent and 
   		 get routed from there, as if the mobile node is at home.
		 Hence if i say ping w.x.y.z from the mobile node, the 
		 out going ip packet should appear as follows

	 ------------------------>
------ 	---------------------------------------------------------			
	| mobile node's |       | mobile node's   |  home agent's|
.....	| home address  |w.x.y.z| address obtained|  address     |
        |               |       |  thru dhcp      |              |
-----	---------------------------------------------------------				 
          src             des            src                des
	
		 After setting the tunnel up, i try to add a default route 
		 to it as follows

      # route add default gw (home agent's address) dev (tunnel-name)
       It says Network Unreacheable.

       So, i try to do this
      # route add -host (home agent's address) gw (default router address  
						   obtained thru dhcp)
					dev (tunnel-name)

	It says Network Unreacheable.

	And some more along these lines. Nothing seems to work. 
	Can anybody help with this?

Thanx in advance
Sashi

Sashikiran Rachakonda
1880 SW 5th 
Portland, OR- 97207
PH: 503-223-4560