Subject: [MEXT] Looking for reviewers of draft-petrescu-autoconf-ra-based-routing-00.txt

From: Alexandru Petrescu <[email-masked]>
Date: Mon, 26 Jul 2010 18:21:18 +0200

Hi,

I am looking for reviewers of

             draft-petrescu-autoconf-ra-based-routing-00.txt
http://tools.ietf.org/html/draft-petrescu-autoconf-ra-based-routing-00
       "Router Advertisements for Routing between Moving Networks"

When/if the reviewing process takes off (comments, modifications) the
goal would be pursue it along the INFORMATIONAL or EXPERIMENTAL
tracks.

Thanks,

Alex

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From: Antti Mäkelä <[email-masked]>
Date: Wed, 28 Jul 2010 15:08:07 +0300 (EEST)

Hi,

   The basic premise is, in my opinion, no different from standard 
stateless autoconfig setup where routers change - only, in this case they 
are advertising a specific prefix instead of default gateways. A form of 
ad-hoc routing, as such.

   Have you checked about alternative solutions used in e.g. wireless 
sensor networks, like AODV and similar protocols? Such setups would allow 
for messages to traverse multiple hops as well.

   One issue you briefly raise in your draft is the concept of mobile 
router and who owns the prefix - but this should be expanded a bit. Are 
you basically running in environment where if you can authenticate 
routers, you can trust them not to claim other networks than what they 
own?

   On the scenario of 3 MR's - I'm not sure if I see this correctly, but is 
MR2, in essence, resending the RA packet it receives from MR1 so that MR3 
can see it?

   If so, what happens in scenarios where same packet is received via 
multiple paths, e.g. when there is another router ("MR4") topologically 
near MR2 and both MR2 and MR4 send MR1's RA packet to MR3. How does MR3 
decide what path to take?

   On security - you are basically going with SEND and assuming closed 
enviroment, where if the RA's source address is authenticated, this 
implies that the prefix advertisement can be trusted. Is this true even 
when not connected to the Internet - I'd think that a misbehaving, 
compromised, or even misconfigured MR could easily claim to represent a 
bunch of networks who it does not really own. At least this could result 
in traffic ending up at black hole.
   Closed-environment specific solutions can of course be come up with - 
such as pre-distributing authentication keys for each prefix.
   Maybe a simple solution would be to require the router to send a 
SEND-protected keepalive packet from each of it's ingress-side address (in 
your diagrams, MR2 would receive some sort of confirmation packet from 
2001:1::1 before it could accept the RA as valid.

   Specific comments on draft text:

   What does "Fixed scene" mean?

   In portion where you handle route deletion due to timeouts, I think 
steps (5) and (6) should be reversed and (7), the re-insertion removed. 
Perhaps the RS should be sent a few seconds before the timer expires "Hey, 
I'm about to stop forwarding traffic to your prefix, if you don't want to 
happen tell me now".

--
- Antti Mäkelä | Researcher -
- Department of communications and networking -
- Aalto University -