Subject: Re: [MOBILE-IP] Comment Please: Placement for Home Address option header

From: Richard Draves <[email-masked]>
Date: Thu, 16 Nov 2000 22:20:52 -0800

> PS: I don't believe nothing should be done but there is a
> working solution
> today then we should adopt it *now* and keep the door open.

Mandating that the Home Address option appear before the Fragment header
does not keep the door open for using ESP instead of AH. It slams the door
shut.

Rich

---

From: Francis Dupont <[email-masked]>
Date: Sat, 18 Nov 2000 17:47:30 +0100

=> the door was already shut by RFC 1825 and 2401, ie. far before the
first mobile IPv6 draft. I don't know if you propose to use ESP in
transport mode but in this case "In general, a packet's source address
MUST match the SA selector value" applies then this doesn't work.
For ESP in tunnel mode the argument is a bit different because RFC 2401
is not very clear about this but many IPsec implementations check to outer
source address then for interoperability reasons the Home Address MUST
appear before ESP in tunnel mode.

If you read my draft (draft-dupont-destoptupd-00.txt) you can see I tried
to clarify things, not to add new constraints (no real new "MUSTs").
For instance, most things are for the sending side: at the receiving
side most of old "SHOULDs" remain but if RFC 2460 mandates to be able
to decode headers in near any order the advanced API (and any reasonable
API) doesn't give the freedom to do silly things.

Thanks

[email-masked]

PS: I am updating an other draft (draft-ietf-ngtrans-hometun-00.txt)
with many considerations about real world problems with ESP in tunnel
mode then if you'd like to reuse mobile IPv6 signaling in a VPN world
you can join us but this will be a long term work!