Subject: [nemo] Comments on MRTP

From: "wlyu" <[email-masked]>
Date: Tue, 1 Apr 2003 23:03:50 +0800

Hi  T.j,

>When the HA_MR receives the routing information from the mobile router
>through the bidirectional tunnel, it adds the corresponding routes to
>its routing table with the next hop set to the mobile router's address,
>in case of IPv6 MR's link local address.  This next hop address is
>obtained from the source address of the inner packet.  The HA_MR in
>turn propagates this information when it sends routing updates to other
>routers on the mobile router's home link.

when HA_MR to do so, the  bidirectional tunnel must have been setup
between MR and HA_MR,  yes or no?

So when the MR moves to foreign link, it first acts as an normal MN to 
interchange binding information with HA_MR, before the establishment of
tunnel, HA_MR can't receive  routing information from MR. 
So, before the process is finished, MR can't serve the nodes behinds it ?

Maybe it's about implementation,but I still to ask the question:-)

Thanks  a lot.

Wanrong Yu

.

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From: "TJ" <[email-masked]>
Date: Tue, 1 Apr 2003 14:12:47 -0300

----- Original Message -----
From: wlyu <[email-masked]>
To: T.J. Kniveton <[email-masked]>
Cc: <[email-masked]>
Sent: Tuesday, April 01, 2003 12:03 PM
Subject: Comments on MRTP

> between MR and HA_MR,  yes or no?

I^m not sure I understand your question -- when the HA_MR does -what-, the
tunnel must have been set up?

> tunnel, HA_MR can't receive  routing information from MR.

Yes, I agree with you. For the most part, the MR looks like a MN to the
HA_MR (with some exceptions). So, when the MR moves, it does what any MN
does on its uplink: first, establishes connectivity, then sends a binding
update. Along with the BU, it will also change the routing for the mobile
network, either explicitly or implicitly.

> So, before the process is finished, MR can't serve the nodes behinds it ?

Well it depends on what you mean by serve. In the same way a MN will have to
buffer packets for its own applications during a handover (until connection
is re-established), the MR will do the same for other nodes. But it should
still have a connection on the mobile network link, and I would say that it
is still serving those MNNs.

> Maybe it's about implementation,but I still to ask the question:-)

Yes, it{s about implementation - but in theory, it is very similar to other
cases when a network link goes down and up again due to changing physical
topology.

> Wanrong Yu

Sure. -TJ

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From: "Wanrong Yu" <[email-masked]>
Date: Wed, 2 Apr 2003 22:40:11 +0800

Hi  T.j,
> tunnel must have been set up?

Sorry for my vague expression.
I jsut mean when HA_MR  receives the routing information 
from the mobile router.

Wanrong Yu

---

From: "Wanrong Yu" <[email-masked]>
Date: Sat, 12 Apr 2003 22:23:20 +0800

Hi  T.j,

Some comments again.

>4.2. Implicit Signaling

  >       In general, implicit signaling means that signaling is not necessary
  >       because of the implication of other factors.  When a mobile router sends
  >       a binding update to its home agent, the home agent knows which prefixes
  >       are assigned to the router, and it sets up the static route and begins
  >       forwarding traffic to the mobile network.  

What will  happen if the mobile router sends a binding update to its home agent 
-only-  want  itself  to be regarded as a normal mobile node, not a mobile router?

According to the draft,  after receiving a binding update from a mobile router,
the HA  sets up the static routes belong to the mobile route automatically, 
so in the upper scenario, the HA does unnecessary  work, wastes resources 
and may  introduce new security problem.

 Does it a problem or i am just worry unnecessarily:-)

Thanks a lot!

Wanrong Yu

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From: "T.J. Kniveton" <[email-masked]>
Date: Sat, 19 Apr 2003 11:09:52 -0700

Hi, I was on vacation when you wrote this; now I'm back.

> Does it a problem or i am just worry unnecessarily:-)

Well, I would say that's the price you pay if you want to use implicit
signaling: the MR is implicitly assumed to be a MR. I wouldn't say that it's
a lot of work to set up a route in the HA, relative to all the work it must
do to complete a home registration.

What is the security problem you have in mind?

TJ

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From: "Wanrong Yu" <[email-masked]>
Date: Tue, 22 Apr 2003 09:48:10 +0800

Hi, TJ

> do to complete a home registration.

Oh, I see. You mean we should use explicit signaling as more as possible.

> What is the security problem you have in mind?

I don't have detailed examples in my mind. I just think  it is dangerous that
the MR does things unnecessary, for I am affrightted by Distributed Denial of Service(DDoS) and 
I am afraid that maybe the same thing will happen to MR , hehe.

Now I think it is not a serious problem, maybe not a problem at all!

Wanrong Yu