Subject: Re: Revised resolution Proposal for LLMNR Issue 38: DNS Proxy undefined

From: [email-masked] (Andreas Gustafsson)
Date: Tue, 13 May 2003 17:20:27 -0700 (PDT)

Bernard Aboba writes:
> "Propagation of LLMNR packets on the local link is considered sufficient
> to enable name resolution in small networks. The assumption is that if a
> network has a home gateway, then the network either has DNS and DHCPv4
> servers or the home gateway provides DHCPv4 and DNS server functionality.
> By providing Dynamic Host Configuration Service for IPv4 (DHCPv4), as
> well as a DNS server with support for dynamic DNS, which is also
> authoritative for the A RRs of local hosts, it is possible to support
> resolution of local host names over IPv4.

At the risk of repeating myself: there is no requirement that the DNS
server is on the local network or the DNS functionality is provided by
the home gateway.  If a network has a gateway, it can use DNS servers
anywhere on the Internet.

> For small IPv6 networks, equivalent functionality can be provided by
> implementing Dynamic Host Configuration Service for IPv6 (DHCPv6) for DNS
> configuration [DHCPv6DNS], as well providing a DNS server with support for dynamic DNS,
> which is also authoritative for the AAAA RRs of local hosts, it is
> possible to support the resolution of local
> host names over IPv6 as well as IPv4. "

I'm unable to parse this sentence.

> This should be adequate as long as home gateways implementing DNS
> configuration also support dynamic DNS in some form."

Again, there is no need for dynamic DNS to be supported specifically
by the gateway.

I suggest replacing the three quoted paragraphs above with the
following single paragraph, which purposely omits any text implying
that home gateway is the specific entity that provides DHCPv4, DHCPv6,
recursive DNS, or dynamic authoritative DNS service:

  "Propagation of LLMNR packets on the local link is considered
  sufficient to enable name resolution in small networks. The assumption
  is that if a network has a home gateway, DHCP and DNS are also
  available, and A and/or AAAA RRs of local hosts can be registered
  using dynamic DNS."

> For example, a home network may provide a DHCPv4 server but may not
> support DHCPv6 for DNS configuration [DHCPv6DNS]. In
> such a circumstance, IPv6-only hosts will not be configured with a DNS
> server. Where a DNS server is configured but
> does not support dynamic client update
> over IPv6 or DHCPv6-based dynamic update, hosts on the home network
> will not be able to dynamically register or resolve the names of
> local IPv6 hosts. If the configured DNS server
> responds to AAAA RR queries sent over IPv4 or IPv6 with an authoritative
> name error (RCODE=3), then it will not be possible to resolve the names
> of IPv6-only hosts. In this situation,  LLMNR over IPv6 can be used for
> local name resolution. "

The above paragraph is hopelessly confused with regards to recursive
versus authoritative servers.  When a host is "configured with a DNS
server" using DHCP, it is configured with a *recursive* server, while
the server that needs to support dynamic update is the server
authoritative for the host's domain name.  These are two completely
separate servers, but the text seems to imply that they are one and
the same. I suggest this paragraph be removed.
-- 
Andreas Gustafsson, [email-masked]

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From: Bernard Aboba <[email-masked]>
Date: Tue, 13 May 2003 17:08:31 -0700 (PDT)

> anywhere on the Internet.

Not sure why you've chosen to comment on the old text rather than the new
proposed text.

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From: [email-masked] (Andreas Gustafsson)
Date: Tue, 13 May 2003 17:51:41 -0700 (PDT)

> Not sure why you've chosen to comment on the old text rather than the new

Pardon me, I didn't notice the following piece of text had been

> configuration also support dynamic DNS in some form."

The rest of the text I quoted and commented on was, as far as I can
see, the new proposed text.
-- 
Andreas Gustafsson, [email-masked]