Hi Richard,
If both egress routers are advertising default routes, then I see no problem with the stub network deciding which to choose. If they have different costs, then definitely the two should be advertising different costs. If the meter network only wants to accept traffic to a particular prefix, then it should only be advertising that.
I do think we need to better define what exactly is an Edge Router in and out of a 6lowpan context. In general, I think of an Edge Router as nothing more than a router that routes between an L2N network to a non- L2N network. In the 6lowpan context, we typically associate an Edge Router with one that also maintains the "whiteboard" for nodes in the 6lowpan network. However, I'm not sure we need to bind them together.
Specific to the 6LoWPAN ND draft, you do bring up an important case - one where two or more Edge Routers are not connected by a "backbone" network. I think there are interesting questions there that are not dealt with in the current 6LoWPAN ND draft (e.g. how is the whiteboard information distributed between edge routers if at all? can we have a particular whiteboard specific for a prefix maintained at only the Edge Router that advertises that prefix? do whiteboards have to be maintained at edge routers?). We should probably open a new thread on this topic in the 6LoWPAN ML...
-- Jonathan Hui On Apr 10, 2009, at 1:01 PM, Richard Kelsey wrote:
From: Carsten Bormann <[email protected]> Date: Fri, 10 Apr 2009 19:00:42 +0200 (I don't tend to think about the case where there is no Edge Router -- ...) I have a question on this, stemming from my lack of familiarity with the details of IP routing. Suppose I have a 6LowPAN/ROLL network being used for energy management in a home. The network includes the electric meter, which has a backhaul connection back to the utility. The utility, being very protective of its backhaul network, has a firewall in the meter to keep out everything except the utility's own traffic. Given the presence of the firewall, does it still make sense to use the meter as an Edge Router? -Richard Kelsey _______________________________________________ Roll mailing list [email protected] https://www.ietf.org/mailman/listinfo/roll
_______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
