Re: [dhcwg] MTU option for DHCPv6?

"Templin, Fred L" <Fred.L.Templin@boeing.com> Thu, 28 July 2016 15:03 UTC

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From: "Templin, Fred L" <Fred.L.Templin@boeing.com>
To: Ian Farrer <ianfarrer@gmx.com>, "Bernie Volz (volz)" <volz@cisco.com>
Thread-Topic: [dhcwg] MTU option for DHCPv6?
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Date: Thu, 28 Jul 2016 15:03:10 +0000
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Subject: Re: [dhcwg] MTU option for DHCPv6?
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Hi Ian,

> -----Original Message-----
> From: Ian Farrer [mailto:ianfarrer@gmx.com]
> Sent: Thursday, July 28, 2016 1:49 AM
> To: Bernie Volz (volz) <volz@cisco.com>
> Cc: <dhcwg@ietf.org> <dhcwg@ietf.org>rg>; Templin, Fred L <Fred.L.Templin@boeing.com>
> Subject: Re: [dhcwg] MTU option for DHCPv6?
> 
> Hi Bernie,
> 
> It sounds like Fred is looking for a DHCPv6 equivalent of DHCPv4 option 26 which (as I understand it) allows the DHCP server to tell the
> client the interface MTU to use on the link. Is this the same option as the one that you’re referring to?

Yes; that is what I was thinking.

> I can also see a use for having this information being sent to the client as we plan to use large MTUs to clients. From my perspective,
> having this information inside the PIO would be most useful.
> 
> @Fred, if the MTU was carried as an option inside the PIO, and there was a way of putting the PIO into DHCP, would this work for you?

I'm not sure I see putti ng the MTU option inside the PIO, because there may be many
PIOs but only one MTU value. Can we have both?

Thanks - Fred
fred.l.templin@boeing.com

> Ian
> 
> 
> > On 28 Jul 2016, at 00:14, Bernie Volz (volz) <volz@cisco.com> wrote:
> >
> > I'm not sure I fully follow.
> >
> > The v4 MTU option is the client telling the server how much it can receive.
> >
> > I'm not sure why the client wouldn't just use a large buffer (64K) as it isn't likely to need many of these buffers? The server is often
> more restrictive since it might be processing many requests at once.
> >
> > And, why would you need to have the server send so much data that the client might not be able to receive it all?
> >
> > BTW: I think when this came up during the writing of 3315, it was thought that having the client use a 64K buffer wasn't really an
> issue.
> >
> > - Bernie
> >
> > -----Original Message-----
> > From: Templin, Fred L [mailto:Fred.L.Templin@boeing.com]
> > Sent: Wednesday, July 27, 2016 5:24 PM
> > To: Bernie Volz (volz) <volz@cisco.com>om>; <dhcwg@ietf.org> <dhcwg@ietf.org>
> > Subject: RE: MTU option for DHCPv6?
> >
> > Hi Bernie,
> >
> > I'm operating on a link where I don't need to get any configuration information from RS/RA - everything comes from DHCPv6. So,
> ideally, I would like to see DHCPv6 provide an MTU option and a Prefix Information Option - then I would have everything I need so
> that I don't have to use a vendor-specific option. Would that be possible?
> >
> > Thanks - Fred
> >
> >> -----Original Message-----
> >> From: Bernie Volz (volz) [mailto:volz@cisco.com]
> >> Sent: Wednesday, July 27, 2016 2:02 PM
> >> To: Templin, Fred L <Fred.L.Templin@boeing.com>om>; <dhcwg@ietf.org>
> >> <dhcwg@ietf.org>
> >> Subject: RE: MTU option for DHCPv6?
> >>
> >> Hi Fred:
> >>
> >> Nothing has been proposed that I can recall. The issue really hasn't come up (to date).
> >>
> >> - Bernie
> >>
> >> -----Original Message-----
> >> From: dhcwg [mailto:dhcwg-bounces@ietf.org] On Behalf Of Templin, Fred
> >> L
> >> Sent: Wednesday, July 27, 2016 4:10 PM
> >> To: <dhcwg@ietf.org> <dhcwg@ietf.org>
> >> Subject: [dhcwg] MTU option for DHCPv6?
> >>
> >> Just curious - is there now (or has there ever been proposed) an MTU
> >> option for DHCPv6 in the same way that DHCPv4 has an MTU option?
> >>
> >> Thanks - Fred
> >>
> >> _______________________________________________
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> >
> >
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