[Dnsmasq-discuss] Router Advertisement: Prefix-Specific Options?

[Luis Marsano]

Sorry for the delay: I had to learn to patch and use a cross-compiling
toolset.
The update is excellent!
Everything seems to work as stated:

   - router advertisement log messages no longer indicate explicit
   dhcp-ranges as constructed
   - 'dig' no longer shows duplicate AAAA records for explicit dhcp-range
   addresses
   - 'ip -6 addr show' reports 'preferred_lft 0sec' for explicit,
   deprecated dhcp-range addresses and 'preferred_lft' non-0 for constructed,
   non-deprecated dhcp-range addresses.

I'll keep testing and report any issues as they emerge, but that looks
unlikely from the elegant change in your code.
Thanks again for this wonderful project!

On Sat, Jun 2, 2018 at 9:21 AM Simon Kelley <simon at thekelleys.org.uk> wrote:

> I just committed
>
>
> http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=c488b68e75ee5304007eef37203c4fc10193d191
>
> which suppresses construction of a dhcp-range if there's an explict
> dhcp-range already.
>
> Testing would be very useful.
>
>
> Cheers,
>
> Simon.
>
>
> On 19/04/18 03:38, Luis Marsano wrote:
> > Simon Kelley <simon at thekelleys.org.uk> wrote:
> >
> >> Apologies, there's no way to sue the solution I suggested in current
> >> dnsmasq, it was a possible future enhancement.
> >>
> >> On 17/04/18 00:16, Luis Marsano wrote:
> >>> Yes, I’d expect that to work, though I’d only know after testing.
> >>> Is there a way to do that?
> >>> I was using the constructor option to handle dynamic prefixes, which
> >>> also need to be advertised.
> >>> The option
> >>>> dhcp-range=set:lan,::,constructor:br-lan,ra-stateless,ra-names,12h
> >>> advertises dynamic prefixes **and** static prefixes: whatever is bound
> >>> to the interface, which seems an all or none proposition to me.
> >>> If I could exclude the static prefix from the constructed
> >>> advertisements, that would work.
> >>
> >> How would you tell which prefixes were static, and which dynamic?
> >
> > I'd know from having to explicitly setup the static prefixes myself
> rather than getting them automatically.
> > IPv6 prefixes from the 6in4 tunnel broker are static: 6in4 is a static
> mechanism and the tunnel broker gave me static addresses and prefixes to
> set up.
> > The other global IPv6 addresses and prefixes are potentially dynamic,
> and automatically appear by enabling IPv6 on the WAN interface: DHCPv6-PD
> gets a prefix from my ISP, and the openWRT/LEDE router automatically
> assigns a subnet from that to its LAN interfaces.
> > Though I could write out the current prefixes, I have no assurance
> they'll remain the same later.
> >
> >>> If I could simply pass an additional option for the static prefix, that
> >>> would also work.
> >>> Is there a way to do either?
> >>> I’m sorry if I missed it in the manual.
> >>
> >> You didn't. I don't think there's any way to do what you want in the
> >> current release of dnsmasq. We have to invent a new function to do it.
> >
> > With the approach you postulated, I might try something like
> >
> >
> dhcp-range=set:lan,::,constructor:br-lan,exclude:2001:db8::,ra-stateless,ra-names,12h
> > dhcp-range=set:lan,2001:db8::,ra-stateless,ra-names,deprecated
> >
> > I was imagining an approach like
> >
> > dhcp-range=set:lan,::,constructor:br-lan,ra-stateless,ra-names,12h
> > dhcp-range=set:lan,2001:db8::,ra-stateless,ra-names,deprecated
> >
> > that merges options and overrides according to some precedence like
> order or specificity.
> > I'm not sure about the best design for a new feature: according to
> https://tools.ietf.org/html/rfc4861#section-6.2.3 router advertisements
> allow each prefix to have its own options, so either design might suffice.
> > I was also considering an alternative based on the tag system, though
> I'm not sure it's meant for that.
> >
> > Your project is great: whatever solution you think is best is probably a
> good one.
> >
> >> Cheers,
> >>
> >> Simon.
> >
> > Thanks
> >
> >>> Thanks,
> >>> Luis
> >>> *From: *Simon Kelley <mailto:simon at thekelleys.org.uk>
> >>> *Sent: *Monday, April 16, 2018 6:37 PM
> >>> *To: *dnsmasq-discuss at lists.thekelleys.org.uk
> >>> <mailto:dnsmasq-discuss at lists.thekelleys.org.uk>
> >>> *Subject: *Re: [Dnsmasq-discuss] Router Advertisement: Prefix-Specific
> >>> Options?
> >>>
> >>> Would this be solved by not constructing a prefix advertisement for
> >>> 2001:db8:: when it's already explicitly configured?
> >>>
> >>>
> >>> Cheers,
> >>>
> >>> Simon.
> >
> > _______________________________________________
> > Dnsmasq-discuss mailing list
> > Dnsmasq-discuss at lists.thekelleys.org.uk
> > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
> >
>
>
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