draft-ietf-dnsop-ipv6-dns-issues-02.txt

bind-3.2.

   acceptable. An interesting alternative would be to use dynamic
   synthesis as in [DYNREVERSE].



6. 6to4

   6to4 addresses can be published in the forward DNS, however special
   care is needed in the reverse tree. See [6to4ReverseDNS] for details.
   The delegation of 2.0.0.2.ip6.arpa. is suggested in [6to4ARPA],
   however, delegations in the reverse zone under 2.0.0.2.ip6.arpa are
   the core of the problem. Delegating the next 32 bits of the IPv4
   address used in the 6to4 domain won't scale and delegating on less
   may require cooperation from the upstream IPSs. The problem here is
   that, especially in the case of home usage of 6to4, the entity being
   delegated the x.y.z.t.2.0.0.2.ip6.arpa. zone (the ISP) may not be the
   same as the one using 6to4 (the end customer).  the

   Another problem with reverse DNS for 6to4 addresses is that the 6to4
   prefix may be transient. One of the usage scenario of 6to4 is to have
   PCs connected via dial-up use 6to4 to connect to the IPv6 Internet.
   In such a scenario, the lifetime of the 6to4 prefix is the same as
   the DHCP lease of the IPv4 address it is derived from. It means that
   the reverse DNS delegation is only valid for the same duration.

   A possible approach is not to populate the reverse tree DNS for 6to4
   addresses. Another one is to use dynamic synthesis as described in
   [DYNREVERSE].




7. Recursive DNS server discovery

   [DNSdiscovery] has been proposed to reserve a well known site local
   unicast address to configure the DNS resolver as a last resort
   mechanism, when no other information is available. Another approach
   is to use a DHCPv6 extensions [DHCPv6DNS].



8.  DNSsec

   There is nothing specific to IPv6 or IPv4 in DNSsec. However,
   translation tools such as NAT-PT [RFC2766] introduce a DNS-ALG that
   will break DNSsec by imposing a change in the trust model. See [DNS-
   ALG] for details.



9. Security considerations

   Using wildcard DNS records in the reverse path tree may have some
   implication when used in conjunction with DNSsec.  Security
   considerations for referenced documents are described in those memos
   and are not replicated here.



10. Author addresses

   Alain Durand
   SUN Microsystems, Inc
   17 Network circle UMPK17-202
   Menlo Park, CA, 94025
   USA
   Mail: [e-mail]

   Johan Ihren
   Autonomica
   Bellmansgatan 30
   SE-118 47 Stockholm, Sweden
   Mail: [e-mail]



11. References

   [RFC1918] Address Allocation for Private Internets. Y. Rekhter, B.
             Moskowitz, D. Karrenberg, G. J. de Groot, E. Lear. February
             1996.

   [RFC2766] Network Address Translation - Protocol Translation (NAT-
   PT).
             G.  Tsirtsis, P. Srisuresh. February 2000.

   [RFC3041] Privacy Extensions for Stateless Address Autoconfiguration
   in IPv6,
             T. Narten, R. Draves, January 2001.

   [RFC3152] Delegation of ip6.arpa, R. Bush, August 2001.

   [RFC3363] Representing Internet Protocol version 6 (IPv6) Addresses
             in the Domain Name System (DNS), R. Bush, A. Durand, B.
             Fink, O.  Gudmundsson, T. Hain. August 2002.

   [DYNREVERSE] Dynamic reverse DNS for IPv6, A. Durand,
             draft-durand-dnsops-dynreverse-00.txt, work in progress.

   [DNS-ALG] Issues with NAT-PT DNS ALG in RFC2766, A. Durand,
             draft-durand-v6ops-natpt-dns-alg-issues-00.txt, work in
             progress.

   [LOCAL] Operational Guidelines for "local" zones in the DNS,
             Kato, A., Vixie, P., draft-kato-dnsop-local-zones-00.txt,
             work in progress.

   [ICMPNL] Use of ICMPv6 node information query for reverse DNS lookup,
             Jun-ichiro itojun Hagino, draft-itojun-ipv6-nodeinfo-
             revlookup-00.txt, work in progress.

   [IPv6ADDRARCH] IP Version 6 Addressing Architecture, R. Hinden,
             draft-ipngwg-addr-arch-v3-11.txt, work in progress.

   [6to4ARPA] Delegation of 2.0.0.2.ip6.arpa, Bush, R., Damas, J.,
             draft-ymbk-6to4-arpa-delegation-00.txt, work in progress.

   [6to4ReverseDNS] 6to4 and DNS, K. Moore, draft-moore-6to4-dns-03.txt,
             work in progress.

   [DNSdiscovery] Well known site local unicast addresses for DNS
   resolver,
             A. Durand, J. hagano, D. Thaler, draft-ietf-ipv6-dns-
             discovery-07.txt, work in progress.

   [DHCPv6DNS] DNS Configuration options for DHCPv6, Droms, R.
             draft-ietf-dhc-dhcpv6-opt-dnsconfig-02.txt, work in
             progress.



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