Subject: RE: Router Lifetime question

From: "Peter Barany" <[email-masked]>
Date: Thu, 15 May 2003 13:29:31 -0500

What I mean to say is that the parameter AdvDefaultLifetime MUST be either
zero or between MaxRtrAdvInterval and 9000 seconds (IPv6) per RFC 2461. Same
thing for IPv4 per RFC 1256 (only the parameter is Advertisement Lifetime).
The inconsistency (for lack of a better word) is that the Router Lifetime
field is 16 bits and if set to anything greater than 9000 seconds then this
would violate the specifications. So, if it is set to 18.2 hours (e.g., for
some wireless cellular links) it violates the specs.

Pete

-----Original Message-----
From: Erik Nordmark [mailto:[email-masked]]
Sent: Thursday, May 15, 2003 1:20 PM
To: Barany, Peter [RICH1:2H16:EXCH]
Cc: [email-masked]'
Subject: Re: Router Lifetime question

> A question regarding RFC 2461. Unless I am missing something, there seems
to
> be some inconsistency in Sections 6.2.1 and 4.2 of RFC 2461 regarding the
> value of the Router Lifetime. How is this resolved? See below. Thanks.

I don't see an inconsistency - can you explain what you think
is inconsistent?

    Erik

---

From: "Peter Barany" <[email-masked]>
Date: Fri, 16 May 2003 07:53:57 -0500

Perfect. That's what I wanted to know ... the client/receiver
interpretation. Thanks.

Pete

-----Original Message-----
From: Erik Nordmark [mailto:[email-masked]]
Sent: Friday, May 16, 2003 2:27 AM
To: Barany, Peter [RICH1:2H16:EXCH]; [email-masked]
Cc: 'Erik Nordmark'; [email-masked]'
Subject: RE: Router Lifetime question

> some wireless cellular links) it violates the specs.

Thanks, now I understand your point.

While the wording might be unfortunate and perhaps confusing, saying that
2^^16 seconds is 18.2 hours is correct.
Even though the sender will not use more than 9000 seconds the protocol
doesn't, and presumably shouldn't, have the receivers reject RAs with a
router lifetime that is larger per the "consevative in what you send; 
liberal in what you accept" principle.

So if we change the sentence in 4.2 from:
	The maximum value corresponds to 18.2 hours.
to
	The field can contain values up to 65535 and receivers should
	handle any value, while the sending rules in section 6 limit
	the lifetime to 9000 seconds.
would that be better?

  Erik