Dual-Stack Approach

• when adding IPv6 to a system, do not delete IPv4

  • this multi-protocol approach is familiar and well-understood (e.g., for AppleTalk, IPX, etc.)
  • note: in most cases, IPv6 will be bundled with new OS releases, not an extra-cost add-on

• applications (or libraries) choose IP version to use

  • when initiating, based on DNS response:
    • if (dest has AAAA or A6 record) use IPv6, else use IPv4
  • when responding, based on version of initiating packet

• this allows indefinite co-existence of IPv4 and IPv6, and gradual app-by-app upgrades to IPv6 usage

Notes: