IPv6 DNS issues

1
IPv6 DNS issues

• draft-ietf-dnsop-ipv6-dns-issues-00.txt
• Alain.Durand_at_sun.com

2
Draft objective

• Accepted as wg document last meeting
• Document IPv6 related issues
• Proposed operational recommendations
• Candidate for BCP or Informational

3
Name space continuity

• Every recursive DNS server SHOULD be either
  IPv4-only or dual stack.
• Every single DNS zone SHOULD be served by at
  least one IPv4 reachable DNS server
• This recommendation could be revisited if/when
  translation techniques between IPv4 IPv6 are
  deployed.

4
Local scope addresses

• Link local addresses SHOULD NOT be published in
  the DNS.
• Site local addresses SHOULD NOT be published in
  the public DNS. They MAY be published in a site
  view of the DNS if two-face DNS is deployed.
• Question
• Can we recommend to put SL in the .local.arpa (or
  .site.arpa) zone?

5
SL Reverse path DNS

• Site local addresses SHOULD NOT be populated in
  the public reverse tree. If two-face DNS is
  deployed, site local addresses MAY be populated
  in the local view of reverse tree.

6
RFC3041 Reverse path DNS

• RFC3041 (privacy extension) addresses SHOULD NOT
  be published in reverse path DNS

7
6to4 Reverse path DNS (unresolved)

• draft-moore-6to4-dns-03.txt
• draft-ymbk-.
• ? Rfc1101 trick (see later)

8
pre-populating Reverse path DNS(unresolved)

• Widespread current practice for ISP serving home
  customers
• 2 reasons
• letting the customer manage the tree
• Dont want to answer calls when something goes
  wrong because of the absence of a PTR
• The size of v6 address space does not allow this
  practice any more

9
Pre-populating solutions

• Wildcard entry
• Several people are uneasy with wildcard in
  general
• DNS record synthesis (reverse forward tree)
• may affect DNSsec
• RFC1101 trick (not in the draft)

10
RFC1101 trick(last resort when no PTR has been
found)

• Network admin configures PTR AAAA for network
  name as in RFC1101
• getaddrinfo()
• If PTR exist, returns it
• If not, zero the interface ID and ask a PTR
• Return string InterfaceID NetName
• getnameinfo()
• If AAAA exist, returns it
• If not and syntax InterfaceID NetName, get
  AAAA for NetName and paste IntefaceID

11
Possible extensions

• Repeat trick at /48 boundary
• InterfaceID SubnetID PrefixName
• Use it for 6to4
• InterfaceID SubnetID 6to4PTR(IPv4
  underlying address)