dhcpcd-discuss

On 18/04/2018 21:38, Ivan Middleton wrote:
> On Wed, Apr 18, 2018 at 08:41:59PM +0100, Roy Marples wrote:
> > dhcpcd runs the hooks at every event, even if the prior one was identical.
>
> I'm curious-- what's an example of a situation where this is necessary?

Client might be recording heartbeat of RA via dhcpcd hooks.

> > A better question to ask is why is your router sending an advertisement
> > every 5 seconds?
>
> According to the spec, an interval as small as 3 seconds is acceptable:
>
> https://tools.ietf.org/html/rfc4861#page-41

Strictly speaking, a 1 second DHCP lease is also permissable and no-one 
has ever said that dhcpcd shouldn't run a hook each time it renews.

But as you're in the mood to argue RFC's, please RFC 7772 which solves 
the problem you're describing:
https://tools.ietf.org/html/rfc7772#section-4
https://tools.ietf.org/html/rfc7772#section-5

The most telling line in that RFC is this:
      the average power budget for
      receiving RAs must be no more than 0.1 mA, or approximately 7 RAs
      per hour.

Roy