Subject: (ngtrans) DNS proxy with 6to4 reverse lookup

From: Feico Dillema <[email-masked]>
Date: Thu, 14 Dec 2000 13:32:32 -0800

Hi,

At the previous ngtrans session the reverse lookup of 6to4 addresses
was discussed. There was some discussion on where the special
support for this should be placed, e.g. in the resolver libs or in the
DNS servers. The disadvantage of the former is existing code-base that
is hard to modify, and `polluting' lots of hosts with functionality
that is expected to become superfluous after some time (it is a
transition after all). In the meantime a solution with the best or
worst of both worlds is around now. I added 6to4 reverse lookup
support to my DNS proxy totd, which can be run on hosts or as frontend
on the local DNS server. It is experimental code, and it is only
tested using nslookup and tcpdump. So, please give me feedback on its
correct or incorrect operation if you're able to do some proper
testing for me ;-}. 

It can be found here:

ftp://ftp.pasta.cs.uit.no/pub/Vermicelli/totd-1.1p5.tgz

it should run on all *BSD like systems, and should be easy to port to
other Unix-like systems. 

Feico.

---

From: "Shiao-Li Charles Tsao" <[email-masked]>
Date: Fri, 15 Dec 2000 09:03:47 +0800

Dear All,
Let me clarify some discussions about the mobile IP interworking issues in
the meeting today.
My first draft about dual-stack model
(http://www.ietf.org/internet-drafts/draft-tsao-mobileip-dualstack-model-01.
txt) is trying to make MNv4 or MNv6 "alive" in IPv6 networks or IPv4
networks if the visited networks do not support DSTM or 6over4. For example,
a MNv6 moves to IPv4 network without 6over4, MNv6 can not get v6 router
advertisement, and will fail in MIPv6 registration. Our draft suggests MNv6
to activate its IPv4 stack, get FAv4 advertisement, obtain an IPv4
COA(assume it's co-located, for example). Once the MNv6 has IPv4 CCOA, it
can generate IPv4-compatiable IPv6 address and register in HAv6. MNv6 in
IPv4 netwrok can talk to HAv6 and CNv6 in IPv6 network using tunneling
mechanisms. (Translator is not necessary in this case. I am sorry that I did
not address this point in the meeting) Regarding of the communication
between MNv6 and CNv4 in IPv4 networks, translators are necessary. That is,
CNv4 sends IPv4 packets to IPv6 home network via translators and then
packets are tunnnelled to the MNv6 in the IPv4 network.

Our proposal did not introduce new protocols or network entities and it is
just to enhanced MN with some "intelligence". Then, MN can obtain a COA and
still has mobility services while visting a network with certain
situations/configurations.

As for the second proposal about Mobile IP application level
gateway(http://www.ietf.org/internet-drafts/draft-tsao-mobileip-00.txt), we
will investigate the security issues and refine the draft soon.

I do appreciate for your comments. Thanks a lot !!!

S. Charles Tsao