Re: [DNA] DNA proposal issue 19 - was [Issue X] LinkID v.s. LandmarkPrefix

[Erik Nordmark <erik.nordmark@sun.com>]

Greg Daley wrote:

> In CPL which is host (only) based, the timers are on the host, and 
> protect
> the host from long term damage, by removing unupdated information 
> at the host.
> 
> Even with the most broken readvartisement scheme for stale information,
> the damage could only occur for a maximum:
> (Router out-of-date timer + Host out-of-date timer)

Are you talking about RFC 2461, or are you talking about a proposal for 
how CPL could work?

    Erik

> If the readvertisement schemes for routers override bad state
> for the hosts, The lifetime for bad information is less than:
> 
> (Router out-of-date timer) + (MaxRtrAdvInterval * ROBUSTNESS)
> 
> By this time, the host should be updated, with fresh state.
> This time is actually related to the readvertising router's actual
> configuration timers (rather than defaults, etc), so it may be 
> significantly lower than the previous cost.
> 
> So if Router out-of-date timer = 1800s (MAXRA) and Host out-of-date 
> timer=3600s
> (2x MAXRA).  This assumes fairly reliable transmission between routers
> (potentially 2 x MAXRA for routers though)).
> 
> Overall the possibility for out of date information is reduced to 2 
> hours
> after change (in that situation, and potentially, 1 hour and a very 
> few seconds
> if the override mechanism is possible).
> 
> Greg