The suggested text is good, except I don't think the first sentence conveys enough information for someone who has not been involved with the discussion about obtaining a list of DNS resolvers. Specifically, no consensus has been reached about what specific issue or issues (in para 1)?
My understanding is that the current active debate is about whether the IETF should take on any work to develop alternatives to DHCP. I suggest the following text as more completely and accurately describing the current situation:
5.2 Obtaining a List of DNS Recursive Resolvers
In scenarios where DHCPv6 is available, a host can discover a list
of DNS resolvers through DHCPv6 "DNS Recursive Name Server" option
[29]. This option can be passed to a host through a subset of DHCPv6
[28].
The IETF is considering the development of alternative mechanisms
for obtaining the list of DNS recursive resolvers when DHCPv6 is
not available. No decision about taking on this development work
has been reached as of this writing (April 2004).
In scenarios where DHCPv6 is unavailable or inappropriate,
mechanisms under consideration for development of dnsop WG include
the use of well-known addresses [26], the use of Router
Advertisements to convey the information [27].
Note that IPv6 DNS resolver discovery is not required for dual-stack
nodes in dual-stack networks as IPv6 DNS records can be queried over
IPv4 as well as IPv6.
Of course, as you wrote, it doesn't appear that many WG members have a strong opinion about the wording of this section.
Also - I finally got around to reviewing why the DHCP option is called "DNS Recursive Name Server". Turns out RFC 1035 refers to "recursive server" (top of page 7) and "recursive service" (several places), so we used the name "DNS Recursive Name Server" for the option. It might be appropriate to retitle this section to be "Obtaining a List of DNS Recursive Servers".
- Ralph
At 01:14 PM 4/16/2004 +0300, Pekka Savola wrote:
Hi,
This has been my concern about modifying the text too much.
There hasn't been too much discussion on the text proposal, so I suspect many in the WG do not care much one way or the other.
I think your suggestion is a good one, and I've now written this section as:
========= 5.2 Obtaining a List of DNS Recursive Resolvers
Obtaining the list of DNS recursive resolvers is a subject of active debate; no consensus has been reached as of this writing (April 2004).
In scenarios where DHCPv6 is available, a host can discover a list of DNS resolvers through DHCPv6 "DNS Recursive Name Server" option [29]. This option can be passed to a host through a subset of DHCPv6 [28].
In scenarios where DHCPv6 is unavailable or inappropriate, mechanisms under consideration for development of dnsop WG include the use of well-known addresses [26], the use of Router Advertisements to convey the information [27].
Note that IPv6 DNS resolver discovery is not required for dual-stack nodes in dual-stack networks as IPv6 DNS records can be queried over IPv4 as well as IPv6. ========
This is what I'm going to use unless I hear objections or suggestions for rewording ASAP.
Note: let's not start a discussion of what those "unavailable or inappropriate" scenarios could be.
On Mon, 12 Apr 2004, Iljitsch van Beijnum wrote: > On 9-apr-04, at 8:26, Pekka Savola wrote: > > > A host can be configured with a list of DNS recursive resolvers > > through the DHCPv6 "DNS Recursive Name Server" option [RFC3646]. > > This option can be passed to a host through a subset of DHCPv6 > > [RFC3736]. Two alternative mechanisms are under consideration: > > the use of well-known addresses [21] and the use of Router > > Advertisements to convey the information [22]. > > > No consensus has been reached as of this writing (April 2004). > > > What does the WG think about this -- That is, > > > Do you have a problem with the above wording? > > Someone who isn't aware of the issue (and if we assume everyone is, why > include any text?) might take this to mean that using DHCP is the way > to go and/or without problems, which IMO isn't the case. I think > working it something like "In situations where DHCPv6 is available, a > host can discover a list of DNS resolvers through [...] Ways to > discover or configure DNS resolvers in situations where DHCPv6 isn't > available or appropriate are under consideration [...]". > > If we feel it's necessary to provide guidance to implementers it would > be good to say something about well-known addresses, as this solution > has the interesting property that it can largely implemented before > it's standardized. Pretty much all that's needed is a global list of > DNS servers that is called upon when no "local" (specific to the active > configuration, those of you who use a Mac know what I mean) information > is available. Obviously the list should be empty at this time. > > . > dnsop resources:_____________________________________________________ > web user interface: http://darkwing.uoregon.edu/~llynch/dnsop.html > mhonarc archive: http://darkwing.uoregon.edu/~llynch/dnsop/index.html >
-- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
. dnsop resources:_____________________________________________________ web user interface: http://darkwing.uoregon.edu/~llynch/dnsop.html mhonarc archive: http://darkwing.uoregon.edu/~llynch/dnsop/index.html
. dnsop resources:_____________________________________________________ web user interface: http://darkwing.uoregon.edu/~llynch/dnsop.html mhonarc archive: http://darkwing.uoregon.edu/~llynch/dnsop/index.html
