arkko-ietf report on ipv4 - ipv6 co-existence.apom · translation – ipv6 hosts reaching ipv4...
TRANSCRIPT
Outline
• Background
• IETF activities
• Solutions & problems
• Next steps
Time
IPv4 Free Pool
Size of the Internet
IPv6 Deployment
The Plan
Time
IPv4 Free Pool
Size of the Internet
IPv6 Deployment
The Reality Today
?
Background
• Does this cause us to reconsider whether our IPv6 deployment and transition toolbox is adequate?
• Or the need for new tools to deal with the pain of IPv4 address shortage?
• The situation with NAT-PT
• Input from the service providers and corporate network managers
• IETF discussions from 2007
This Is Important!
• The way we deploy IPv4 NATs changes as there is less address space
• We cannot deploy IPv6 in all situations where we would like to
• I see many potential future outcomes, some of them bleak
• Is there something that we can do to help provide better solutions and to help IPv4-IPv6 co-existence and IPv6 adoption?
State of the Art • This is not a claim that the existing tools should no
longer be used – for instance, Dual Stack with an IPv4 NAT is still what most networks would likely want to use
• Similarly, existing tunneling mechanisms for IPv6 transition continue to be valid
• Focus is on new situations, such as when a NAT does not even have one address, or when RFC 1918 space runs out
• Avoid the search for a silver bullet
Recent IETF Activities
• Several discussions in Dublin
• An interim meeting in Montreal
• New charter for SOFTWIRE WG
• Proposed new charter for BEHAVE WG
Montreal Outcome • A well attended interim meeting in Montreal on
October 1st-2nd
• Focused on improved IPv4 NATs, tunneling to solve RFC 1918 shortage, and IPv4 – IPv6 translation
• Strong consensus that we need we need both tunneling and translation based solutions to address different scenarios
• A better understanding of how different solutions
Solutions and Problems
• Home gateway and service provider router tunnel IPv4 over IPv6
• Often combined with a NAT on the provider router to share one address
• IPv6 to home gateways as a side effect
Dual-Stack Light – Running Out of RFC 1918 Space�
• Each subscriber gets only a fraction of a public address; a port range
• Can be implemented in various ways: an extension of the tunneling approach, mapping port ranges to IPv6 (A+P), ...
• Again, as a side-effect gateways get IPv6
Shared public address, separate port ranges
NAT stays here Port-based forwarding here
Port Borrowing – Public IPv4 Address Shortage
Translation – IPv6 Hosts Reaching IPv4 Hosts
• An example application is IPv6 hosts connecting to IPv4-only servers
• E.g., Windows 7 Direct Access
• Enables unilateral IPv6 deployment
• Currently uses NAT-PT,
IPv6 host
IPv4 servers
More on Translation
• Work will address four cases: connecting a specific IPvX-only network to the IPvY Internet, with initiation on either side
• IPv6 access to a set of IPv4 servers
• IPv6-only branch office connecting to IPv4 Internet
• IPv4 access to a set of IPv6 servers
• The last IPv4 holdout accessing the IPv6 Internet
More on Translation 2
• Documents under development include framework, packet translation, state maintenance, and DNS parts
• Challenges include DNSSEC and preventing dual stack hosts accidentally selecting a path through a translator
• The two ways to improve over NAT-PT: simply a better specification and focusing on constrained scenarios
• As an example, no DNS tricks needed when
Next Steps • Please provide feedback
• Here, on the list, or in the IETF meetings
• Upcoming meeting in Minneapolis
• Interim meetings in Malta (Jan 20-22)
• Progress the specifications from BEHAVE and SOFTWIRE
•C
Further Reading http://trac.tools.ietf.org/area/int/trac/wiki/v4v6interim http://tools.ietf.org/html/draft-arkko-townsley-coexistence http://tools.ietf.org/wg/softwire http://www.ietf.org/html.charters/softwire-charter.html http://tools.ietf.org/wg/behave http://www.ietf.org/mail-archive/web/behave/current/msg04569.html http://www.ietf.org/mail-archive/web/behave/current/msg04554.html http://tools.ietf.org/id/draft-durand-softwire-dual-stack-lite http://tools.ietf.org/id/draft-bagnulo-behave-nat64 http://tools.ietf.org/id/draft-bagnulo-behave-dns64-00.txt http://tools.ietf.org/id/draft-baker-behave-v4v6-framework-00.txt http://tools.ietf.org/id/draft-baker-behave-v4v6-translation-00.txt RFC 4213 RFC 2766 RFC 4966