[IPv6]Re: How are AdvReachableTime and AdvCurHopLimit in RFC4861 used?

[Ted Lemon <[e-mail]>]

Wow. Thanks. This just goes to show that full text searches aren’t
foolproof—I totally missed that!

Op di 28 mei 2024 om 08:25 schreef Timothy Winters <[e-mail]>

> Hi Ted,
>
> 7.3.2 <https://datatracker.ietf.org/doc/html/rfc4861#section-7.3.2>
> defines the state machines that use ReachTime.
>
> ~Tim
>
> On Sat, May 25, 2024 at 1:50 PM Ole Trøan <otroan=
> [e-mail]> wrote:
>
>> 20 uses of ReachableTime. 8 uses of “Reachable Time”.
>> Read those sections. But it might be hard to understand ND completely
>> unless you read it all.
>> It’s a long document and the most complicated core IPv6 protocol
>> specification.
>>
>> O.
>>
>> On 25 May 2024, at 16:38, Ted Lemon <[e-mail]> wrote:
>>
>> 
>> Right. My question is, where is the rfc that describes what these
>> variables do? Hop
>> Limit is somewhat straightforward, I guess, but where is the rfc that
>> explains what to do with the reachable time? I’m not saying these things
>> don’t exist, but there is no reference to them in this RFC.
>>
>> Op za 25 mei 2024 om 09:58 schreef Mark Smith <[e-mail]>
>>
>>> On Sat, 25 May 2024 at 21:22, Ted Lemon <[e-mail]> wrote:
>>> >
>>> > Maybe we should write this down somewhere…
>>> >
>>>
>>> Pretty sure it is in RFC 4861:
>>>
>>> 6.3.4.  Processing Received Router Advertisements
>>> ...
>>>    If the received Cur Hop Limit value is non-zero, the host SHOULD set
>>>    its CurHopLimit variable to the received value.
>>>
>>> ...
>>> If the received Reachable Time value is non-zero, the host SHOULD set
>>>    its BaseReachableTime variable to the received value.  If the new
>>>    value differs from the previous value,...
>>>
>>> > Op za 25 mei 2024 om 02:05 schreef Erik Kline <[e-mail]>
>>> >>
>>> >> I think they update the per-interface ND state defaults, vis.:
>>> >>
>>> >>
>>> https://elixir.bootlin.com/linux/v6.9.1/source/net/ipv6/ndisc.c#L1457
>>> >>
>>> >> and
>>> >>
>>> >>
>>> https://elixir.bootlin.com/linux/v6.9.1/source/net/ipv6/ndisc.c#L1426
>>> >>
>>> >> On Fri, May 24, 2024 at 1:58 PM Ted Lemon <[e-mail]> wrote:
>>> >>>
>>> >>> We've spent the past half hour in the SNAC interim trying to
>>> understand what these do, and we've come up empty. Are they in fact used?
>>> What do they do? We don't know what values to specify for them in SNAC
>>> router RAs.
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>