Subject: [mif] draft-ietf-mif-dhcpv6-route-option

From: Mikael Abrahamsson <[email-masked]>
Date: Mon, 18 Mar 2013 15:03:34 +0100 (CET)

Hello.

I was going through IETF86 presentations and found the DHCPv6 route option 
draft. I have some thoughts about this subject:

I would like to be able to provision routes based on source address of the 
packet being sent from the host.

Use case:

Two different routers announce two different on-link prefixes. I now want 
to be able to say that a certain route should only be applied towards one 
of the routers for a specific set of source addresses (most likely the 
addresses announced as being on-link by that router but not necessarily 
so).

It feels like my case is close to use case 8 in the draft, but it's not 
clear to me from reading the draft if what I'm proposing is actually 
possible, especially since the format of the route information seems to be 
destination based only?

    2001:db8:1::/64      /---- router a
host -------------------
    2001:db8:2::/64      \---- router b

so I want all packets sourced from 2001:db8:1::/64 to go to router a and 
all packets from 2001:db8:2::/64 to go to router b.

Perhaps I also want to null route 2001:db8:3::/64 if sourced from 
2001:db8:2::/64 plus add a 2001:db8:3::/64 via router a from 
2001:db8:1::/64 (to make sure 2001:db8:2::/64 is never used to reach 
2001:db8:3::/64).

Or I just add a ::/0 source for 2001:db8:3::/64 via router a because this 
is a DMZ that is not reachable via router b at all, so both 
2001:db8:1::/64 and 2001:db8:2::/64 sould use router a to reach 
2001:db8:3::/64.

Adding a source IP field to the route would give a lot of flexibility.

Thougts?

-- 
Mikael Abrahamsson    email: [email-masked]

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From: Ted Lemon <[email-masked]>
Date: Mon, 18 Mar 2013 15:28:18 +0000

On Mar 18, 2013, at 10:03 AM, Mikael Abrahamsson <[email-masked]> wrote:
> I was going through IETF86 presentations and found the DHCPv6 route option draft. I have some thoughts about this subject:
> 
> I would like to be able to provision routes based on source address of the packet being sent from the host.

You should not be expected to be aware of this, since it's quite recent news, but work on this option is going to be removed from the MIF charter, and is officially out of scope for the working group, because it's such a contentious issue, and the working group needs to focus on its core charter.

I think the question you've asked is an interesting one, but until we find a home for this work and get IETF consensus on it, it's moot, since you can't have operational issues with a standard that hasn't been published (at least in theory).

If you are interested in this work, there's been some talk of forming a non-WG mailing list at the IETF for people who want to talk about it.   I would be happy to add you to the list of people who are interested in this topic if you want.

And I do apologize for responding to a technical question with a process answer... :}

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From: Tomek Mrugalski <[email-masked]>
Date: Mon, 18 Mar 2013 18:18:21 +0100

On 18.03.2013 16:28, Ted Lemon wrote:
>> I was going through IETF86 presentations and found the DHCPv6 route
>> option draft. I have some thoughts about this subject:
>> 
A long time ago when mif-dhcpv6-route-option was forming as a rough
merge between 3 drafts we made a decision to make source routing out of
scope. Not because it was not important, but because it would make the
whole concept even more contentious. dhcpv6-route-option is designed to
be extensible. It is possible to define a new option that will convey
information about source routing as well.

> I think the question you've asked is an interesting one, but until we
> find a home for this work and get IETF consensus on it, it's moot,
> since you can't have operational issues with a standard that hasn't
> been published (at least in theory).
In my opinion there should be something published out of this work:
either the route-option itself or a draft that explains why route-option
like solution will not be published in IETF. This is fifth IIRC attempt
to standardize routing configuration over DHCPv6. Even if we abandon
this work, other attempts will be made in the future. It would be good
to have something simple and clear to point to ("don't do this, because
of the following reasons" style of a draft).

> If you are interested in this work, there's been some talk of forming
> a non-WG mailing list at the IETF for people who want to talk about
> it.   I would be happy to add you to the list of people who are
> interested in this topic if you want.
> 
We had technical answers coming all around and it didn't help, so we may
want try a process one as well. ;)

Tomek

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From: Ted Lemon <[email-masked]>
Date: Mon, 18 Mar 2013 17:31:55 +0000

> want try a process one as well. ;)

Indeed so.   But let us keep this discussion off the MIF mailing list; if you read this and want to be added to a discussion list, please reply to me privately and not on the mif list.

Thanks!