[Unstrung-hackers] RPL requirements

Michael Richardson mcr at sandelman.ca
Tue Oct 13 23:22:31 EDT 2015


Vijay Anand R <vjanandrgky at gmail.com> wrote:
> Design Considerations
> ====================
>
> a. The DODAG root is administratively configured to be the
> controller/registrar host.
> b. The DIO message used to build the DODAG would be configured as below.
>     i) The 128 bit DODAGID is the IPv6 Domain ULA address of the host device.

Is it your goal to automatically configure this?
I think that is a mistake: other hosts then have to figure out what DODAGID
to listen to.  I'm not really sure why in the end we have DODAGID looking
like an IPv6 address, it's just 16 bytes.  Instead, I suggest that it be
     414e 494d 4141 4e49 4d41 414e 494d 4141

(Which is just ANIMA in ASCII repeated)

>     ii) PIO option is not required to be distributed to the forwarding
> elements. The ULA address assignment is handled by AN control plane protocol.

The PIO could be turned off, sure.

>     iii) The DODAG operates in Storing Mode of Operation with multicast
> support. P2P traffic is not required to be routed all the way to the DODAG
> root.

sure.

> c. AN is more concerned with the connectivity of devices and hence not
> particular about a objective function. OF0 as defined in RF 6552 is suitable
> enough. Therefore the root and hence the DODAG is grounded.

yes.

> d. The preference bit is the same for all nodes (could be 3).
> e. The Domain ULA address is advertised in the DAO messages as reachability
> information.

That's done with the tree at:
       https://github.com/mcr/unstrung/tree/t10143-prefixes-from-interfaces

It's failing in Travis-CI, because it seems that the 12.04 libboost-dev
does not have binomial-heaps available. I'm deciding what to do about that.

> f. The DAO messages are exchanged over the Overlay network over the IPSEC/GRE
> tunnels. Therefore the DODAG is constructed over overlay network.

Ideally, we need to have -i take a wildcard, and learn operate automatically
on new interfaces.

> g. Any new tunnel interface that is created by AN should be associated with
> RPL.
> h. Election of a new ROOT when the current ROOT goes down could be based on
> the lowest prefixed IPV6 Domain ULA address. This is desirable so that the
> ULA address are assigned incrementally and the node closest to the current
> ROOT could potentially become the new ROOT. This is an implementation detail
> and is not covered in any of the RFCs.

RPL already creates new roots if you use the same DODAGID. There is no need
for a new protocol to perform an election.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        | network architect  [
]     mcr at sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [



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