Re: [Last-Call] Iotdir telechat review of draft-ietf-v6ops-slaac-renum-04

[Ted Lemon <[e-mail]>]

On Oct 20, 2020, at 3:51 PM, Fernando Gont <[e-mail]> wrote:
>> This is relevant because some IoT deployments make use of sleepy devices that may only wake up once per day or even less frequently. The suggested parameters would be inappropriate for such a device.
> 
> Just me double-checking: Do you mean it would be to short for them?
> 
> Please note that the default router lifetime is 1800 seconds. So a host
> that sleeps for longer than that will presumably not have a default router when it wakes up, and would need to do a "refresh" procedure (RS/RA exchange) before it would be able to send a packet, anyway.

Right, in a situation like this, where the network is pretty stable, it would make sense to use longer lifetimes. Also bear in mind that the communication on this network might be between two hosts on the same link—one a data collector and one a reporting device. So the router lifetime might not be an issue. If the communication is going off-network, a longer router lifetime would be required.

>> At the same time such a device likely is not relying on RA, since it
>> would not be awake for periodic refreshes. Nevertheless the operational mitigations section could use some additional verbiage about applicability so that readers do not assume that the advice given there is universally applicable.
> 
> Please clarify the above, and based on that, we could craft some text if
> necessary.

What I’m suggesting is simply that you mention that the defaults you are recommending are really most applicable in home networks, and may not be applicable in various commercial networks, including the IoT deployment I used as an example.  IOW, make it clear that these defaults are not universally applicable. There’s no text right now that says that (unless I missed it).