Subject: [MOBILE-IP] RFC2344bis Reverse Tunneling

From: "Lee, Jiwoong" <[email-masked]>
Date: Fri, 2 Jun 2000 17:22:46 +0900

Hi

There is a part which describes the usage of reverse tunneling for
private ip network.

In Figure A1 of A.1, MN has its IP address, Mc.

I recommend the fact that IP address Mc belongs to address space C,
in lieu of address space A.

Figure A1 itself can lead readers to confusion from the viewpoint that each
of Fa, Fb, Hb, Hc, and Yc follows the corresponding address space.

Jiwoong Lee

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From: Samita Chakrabarti <[email-masked]>
Date: Tue, 6 Jun 2000 17:26:55 -0700

Hi Jiwoong :

> In order to support communications between Mobile node( who has a private
> home address and is located at a private IP network) and a correspondent
> host (who has a public ip address and is located in a public ip network),
>
> how's designing of HA-NAT combination topology ? With this, HA MAY discern
> home ip address and private ip address.
>

As I understand, HA-NAT combination topology design consideration is outside
the scope of mobileip draft. It will be very tricky to specify private address
support for home agent and foreign agent private networks with NATs. This could be
implementation dependent.

We can consider simple scenario for using mobile node with private addresses
and where the COA and HAA are public addresses and the mobile node visits
the foreign agent in a publicly routable network.

Another case is mentioned in the rfc2344-bis, which is MN has private address
and it is always one hop away from the home agent while at home or one hop
away from FA while visiting.

Figure A1: NON-ROUTABLE PACKETS IN DISPARATE ADDRESS SPACES

      Mc               Fa  Fb              Hb  Hc             Yc
   [MN]-----------------[FA]----------------[HA]---------------[Y]
        Addr space A          Addr space B       Addr space C

     Figure A2: IP IN IP REVERSE TUNNELED PACKET FROM FA TO HA
         +-----------------+
         |        +-------+|
         | Fb->Hb | Mc->Yc||
         |        +-------+|
         +--------+--------+

-Samita