Subject: RE: [mobile-ip] I-D ACTION:draft-mccann-mobileip-80211fh-01.txt

From: "Hesham Soliman (EAB)" <[email-masked]>
Date: Wed, 13 Nov 2002 21:37:38 +0100

> >=> Ok, but that was not my point. The point is that the
  > >AR's job is identical to the HA's job. BTW, a host
  > >does not have a routing table, in IPv6 a host has a destination
  > >cache.
  > 
  > I disagree. It is perfectly possible to have a server 
  > sitting in the middle of
  > somebody's network with nothing connected to it acting as 
  > an HA. That doesn't
  > make sense for an AR.

=> The HA is a _router_ not a server. See the definition
of router in RFC2460.

  > > => There are so many architectural and security issues
  > > there.
  > > Architectural: RS's are NOT designed for this use. This
  > > is an abuse of an existing message.
  > 
  > My feeling is that BUs aren't either.

=> BUs are not designed to redirect traffic from
one address to another ??? If you really think so
then this is a comment on MIPv6 in general. 

  > 
  > > Security: How will you secure the RS? If you answer
  > > this question, you can answer the exact same question
  > > about the BU.
  > >
  > 
  > Same way as any security is done for any ND message.

=> Which points to the null set today (not considering
manual config). 

Hesham

---

From: "James Kempf" <[email-masked]>
Date: Wed, 13 Nov 2002 13:15:12 -0800

> => The HA is a _router_ not a server. See the definition

But a router doesn't have to have any hosts connected up to it. Routers beyond
the last hop don't, they just connect up to other routers. For example, Sun
servers can be configured as routers if they have multiple interfaces. "Router"
is a functional designation, it is not a physical designation.

The point I was trying to make is that I hear you assuming the "home network"
must have access routers too and that these must be ARs. This assumption seems
to be deeply embedded into the MIP document, i.e. all the discussions about what
happens when an MN "returns home," so it is not suprising. In fact, it could
ultimately turn out to be the case that 90% of the home agents don't host any
wireless interfaces and are just a routing box with a huge cache and lots of
reliability features sitting in somebody's network doing BUs and RR. The service
provider offering the mobility service might not even be a wireless network
service provider. Nothing in the MIPv6 design requires a home agent to have
wireless access points connected up to it, or even wired access points.

That's why I think an AR is different from an HA, and why I want to preserve and
strengthen that distinction.

> then this is a comment on MIPv6 in general.

They are not designed to change routing unless the address actually does change.
What is happening is that the link suddenly goes away and the host appears on
another one. The address _does not change_ if the PCoA is being used.

A BU is only used when an address change is required.

> => Which points to the null set today (not considering

RFC 2461 specifies AH, the key distribution needs to be worked out. SEND is
working on it, so at least there is an approach. Is BU any better? Which way
should BU be secured, by manual configuration of an IPsec SA, as with the HA
security association, or by RR as with the CN?

            jak