Re: easy to remember addresses and /etc/hosts and DNS

[Kerry Lynn <[e-mail]>]

On Fri, Apr 26, 2019 at 7:36 AM Alexandre Petrescu <
[e-mail]> wrote:

>
>
> Le 26/04/2019 à 12:05, Mark Smith a écrit :
> > On Fri, 26 Apr 2019 at 19:54, Alexandre Petrescu
> > <[e-mail]> wrote:
> >>
> >>
> >>
> >> Le 26/04/2019 à 11:46, Mark Smith a écrit :
> >>> On Fri, 26 Apr 2019 at 19:28, Alexandre Petrescu
> >>> <[e-mail]> wrote:
> >>>>
> >>>>
> >>>>
> >>>> Le 26/04/2019 à 06:31, Brian E Carpenter a écrit :
> >>>>>
> >>>>>
> >>>>> Regards Brian Carpenter
> >>>>>
> >>>>> On 25-Apr-19 21:48, Philip Homburg wrote: ...
> >>>>>> The main example you gave is somebody typing IPv6 literals while
> >>>>>> sitting in a car.
> >>>>>
> >>>>> Indeed, we said from the very beginning (I mean 1994) that users
> >>>>> should never be required to type in IPv6 addresses.
> >>>>>
> >>>>> Is this so hard to avoid?
> >>>>
> >>>> It may be easy to avoid typing IPv6 addresse when DNS was available.
> >>>>
> >>>> But think about three cars in a covoy; the convoy is disconnected from
> >>>> the IPv6 Internet, yet fully connected on IPv6 between all computers
> in
> >>>> the convoy.  Which of the cars should host the DNS server?
> >>>>
> >>>
> >>> All of them.
> >>
> >> Mark,
> >>
> >> Thank you very much for the suggestion.  I will consider it.
> >>
> >> I would like to ask you: is multicast DNS (mDNS) working on a single
> >> subnet only?  Or does it work across subnets?
> >>
> >
> > I'm not an expert in mDNS or related, have just read enough to know
> > what problem they're solving and (very) roughly how it works.
> >
> > DNS Service Discovery is intended to convey that information across
> subnets:
> >
> > http://www.dns-sd.org/
>
> I suppose DNS Service Discovery works ok on IPv6, and over multiple
> subnets, and that it relies on the proper use of IPv6 multicast routing
> protocols.  I never tried IPv6 multicast routing protocols on links
> involving OCB (a kind of stripped ad-hoc WiFi at 5.9GHz).
>
> I suppose the use of DNS resolver address in RA is also an option in
> this space.  I have tried this DNS-in-RA and it works ok.
>
> Whether DNS-in-RA, DNS-SD and mDNS should be used in cars, and how, can
> be a subject of debate.  There is a Problem Statement draft in the
> IPWAVE WG that lists in section "DNS Naming Service" some considered
> problems.
>
> Until these things get fixed (how to use DNS in car convoy?) I need the
> manual configuration of easy to remember link-local addresses
>
> When DNS works in car convoys, I expect other inconvenients using
> name-to-address mappings compared to IP address literals.
>
> I might need to update the DNS servers' files with new IPv6 Link-Local
> address to name mappings, whenever a faulty interface is replaced, or
> when USB interface keys are moved, or when 1Gb Ethernet cards are
> migrated to 10Gb Ethernet.
>
> If I am to update files, why not updating rather the computer startup
> scripts (not DNS)?  These computer startup scripts are present in all
> computers, including embedded, as unencumbered and open source.
>
> Second,
>
> If I use DNS names I must remember a name like:
> front-Lead-First (means the IP address on the front bumper of the
>                    Follower, in the subnet between Lead and First
>                    Follower)
> rear-Lead-First
> front-First-Second
> rear-First-Second
> etc.
> These names are too long to type.  So I would abbreviate them to:
> flf
> rlf
> ffs
> rfs
> etc.
>
> These flf, rlf, etc are no less cryptic than a literal like fe80:1::1 is.
>
> The short IP address literals are loved and understood by more people.
>
> >> (because the numerous computers in these three cars are not all on a
> >> single subnet; they are all interconnected with IP, but there are
> >> multiple subnets with routers in between).
> >>
> >
> > There may be other options that better suit or can be better made to
> > suit what you're trying to do, such as the work done in the Homenet or
> > the ANIMA Working Groups.
> >
> > Autonomic networking (the focus of ANIMA WG), sounds like it might be
> > working on solutions to your problem domain.
> >
> > "Autonomic networking refers to the self-managing characteristics
> > (configuration, protection, healing, and optimization) of distributed
> > network elements, adapting to unpredictable changes while hiding
> > intrinsic complexity from operators and users."
>
> Yes, they should be considered.
>
> I will make this suggestion in the IPWAVE WG for the Problem Statement
> draft.
>
> Alex
>
> >
> >
> > Regards,
> > Mark.
> >
> >> Alex
> >>
> >>>
> >>> http://www.multicastdns.org/
> >>>
> >>> Multicast DNS
> >>> https://www.ietf.org/rfc/rfc6762.txt
> >>>
> >>> There's also a good book on it:
> >>>
> >>> ""Zero Configuration Networking: The Definitive Guide
> >>> https://www.amazon.com/gp/product/0596101007
> >>>
> >>>
> >>> A number of implementations:
> >>>
> >>> https://www.avahi.org/ - Linux
> >>>
> >>> https://developer.apple.com/bonjour/ - Apple, Windows
> >>>
> >>> And if you want to know what inspired it,
> >>>
> >>> "Requirements for a Protocol to Replace the AppleTalk Name Binding
> >>> Protocol (NBP)"
> >>> https://tools.ietf.org/html/rfc6760
> >>>
> >>> This is why you need to explain your problem, not just what you think
> >>> is the solution. You'll get much quicker answers.
> >>>
> >>> <snip>
> >>>
> >
>
>
Alex,

You might want to read https://datatracker.ietf.org/wg/dnssd/about/

Kerry