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IPv6 DNS Discovery Issues. Jaehoon Paul Jeong ETRI paul@etri.re.kr http://www.adhoc.6ants.net/~paul/ 1st March 2004 59th IETF – Seoul, Korea. Recent Decision on IPv6 DNS Discovery. DNSOP Decision
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IPv6 DNS Discovery Issues Jaehoon Paul Jeong ETRI paul@etri.re.kr http://www.adhoc.6ants.net/~paul/ 1st March 2004 59th IETF – Seoul, Korea IETF59 DNSOP WG
Recent Decision on IPv6 DNS Discovery • DNSOP Decision • ADs and Chairs have decided to produce a document outlining the attributes of three DNS discovery approaches; • RA Option • DHCP Option • Well Known Addresses • Document of IPv6 DNS Discovery • Describes the outstanding problems and issues with IPv6 DNS Discovery • Details the following things; • Operational attributes of each solution • Various deployment scenarios • Analysis of a multi-solution resolution • Etc. IETF59 DNSOP WG
DNS Discovery Approaches • RA Option(draft-jeong-dnsop-ipv6-dns-discovery-01.txt) • RA DNS Server option • It can be delivered to IPv6 Host along with IPv6 Prefix Information option. • DHCP Option(draft-ietf-dhc-dhcpv6-stateless-04.txt, RFC 3646) • DHCP Recursive Name Server option • It can be delivered to IPv6 Host by either DHCPv6 server or Stateless DHCPv6 server (DHCP-lite). • Well Known Addresses(draft-ohta-preconfigured-dns-01.txt) • Preconfigured Well Known Anycast Addresses • It can be preconfigured in IPv6 Host. IETF59 DNSOP WG
How to apply each approach? - 1/2 • Ordering between RA Option and DHCP Option • Criterion? • M and O flags IETF59 DNSOP WG
How to apply each approach? - 2/2 • Ordering between two Options and Well-known Addresses • Criterion? • Well-known Addresses are last resort. • When IPv6 Host cannot get DNS server information though both RA and DHCP. • IPv6 Host can configure Well-known Addresses as the most preferable in its configuration file. • IPv6 Host can get the explicit fact that Well-known Addresses for DNS can be used in the site through RA Hint Option. • RA Hint Option indicates that Well-known addresses can be used for DNS name resolution. • RA Hint Option can be implemented by RA DNS Server Option with a new flag, Well-known Addresses for DNS. IETF59 DNSOP WG
Deployment Scenarios • Prefix Delegation Environment • When a leaf router gets a subnet prefix though Prefix Delegation protocol, such as DHCP, DNS server address(es) can be piggybacked. • Leaf router advertises DNS server address(es) with RA options. • Mobile Environment • MIPv6, HMIPv6 and NEMO • Through RA Options, DNS Server Addresses can be piggybacked with CoA Prefix Information. • There is no additional delay to discovery DNS Server. • Well-known addresses can be used for DNS name resolution. • If Hint option for Well-known addresses is used together, Mobile Node will be convinced that it can be served. IETF59 DNSOP WG
Discussion • Any questions or comments… IETF59 DNSOP WG