====== IPv6 ======
===== Tests =====
^ Service ^ Tests Subjects ^
| [[https://www.mythic-beasts.com/ipv6/health-check?domain=onmars.eu|mythic-beasts.com]] | Nameservers, Webserver, Mailserver |
| [[http://test-ipv6.com/|test-ipv6.com]] | Connection, DNS Resolver |
| [[http://ipv6-test.com/|ipv6-test.com]] | Connection, DNS Resolver, Reverse DNS, ICMP, [[http://ipv6-test.com/pingtest/|Ping]], [[http://ipv6-test.com/speedtest/|Speed]], [[http://ipv6-test.com/validate.php|Webserver]] |

===== Tunneling =====
==== 6to4 ====
  * IPv4 World <-> ''192.88.99.1''6to4 relay''2002:x.x.x.x::/48'' <-> IPv6 World
  * ''192.88.99.1'' is an anycast address of the nearest //6to4 relay//
  * ''2002:x.x.x.x::/48'' is an anycast route of the nearest //6to4 relay//
  * On one side of the IPv4 net is an //6to4 relay//, on the other an //6to4 router// or host
  * IPv4 Hosts get an IPv6 Net
  * IPv6 Hosts get nothing (they know "I'm talking to an 'IPv4 host'" but they don't get an IPv4 IP/Net)
  * IPv6 encapsulated in IPv4 \\ IPv4(Type=41, Src=x.x.x.x, Dst=192.88.99.1, Payload=IPv6(Src=2002:x.x.x.x, Dst=Dst))
  * ''2002::/16'' gets an **public** IPv4 Address appended => ''2002:x.x.x.x::/48'' => 16 Bit remaining for subnets.
  * Unmanaged: Automatically finds nearest Router per anycast
  * As an public IPv4 is required, it's hard to NAT

^  Host  ^^  IPv4 only Net  ^  6to4 relay  ^  At least IPv6 Net  ^
^  At least IPv6 Net  ^  6to4 router  ^ ::: ^ ::: ^ ::: ^
| IPv6(Src=2002:x.x.x.x::, Dst=y) |  ->  | IPv4(Type=41, Src=x.x.x.x, Dst=192.88.99.1) + IPv6(Src=2002:x.x.x.x::, Dst=y) |  ->  | IPv6(Src=2002:x.x.x.x::, Dst=y) |
| IPv6(Src=y, Dst=2002:x.x.x.x::) |  <-  | IPv4(Type=41, Src=192.88.99.1, Dst=x.x.x.x) + IPv6(Src=y, Dst=2002:x.x.x.x::) |  <-  | IPv6(Src=y, Dst=2002:x.x.x.x::) |

==== 6in4 ====
  * Like 6to4, but with explicitly configured relays (managed)
  * On both sides of the IPv4 only net are relays or hosts
  * Both have to configure the IPv4 IP of the other endpoint => Only usable for static IPv4 addresses.
  * Not dependent on an ''2002::/16'' net

==== AYIYA ====
  * Solves the NATing problems of 6in4 and 6to4 by using NATable transport protocols (UDP, TCP, SCTP)
  * Prevents spoofing by signing packages
  * Prevents replaying
  * Does **not** encrypt packages
  * Still has problems with dynamic IPv4 addresses (those transport protocols does not support roaming)

==== AICCU ====
  * Software/Protocol developed by SixXS to make 6in4 and AYIYA usable for dynamic IPv4 addresses (informs the other endpoint about new IPv4 address)
  * Also used by HE

==== Address Embedding ====
  * IPv6 representations of IPv4 addresses
  * IPv4-Mapped IPv6 Address: ''::FFFF:x.x.x.x''
    * Only on one host
    * Use IPv6 API for IPv4 (prevents duplicated or complicated code)
    * Can never be seen on the wire
  * IPv4-Compatible IPv6 Address: ''::x.x.x.x''(deprecated)
    * Can be routed and translated to the corresponding IPv4 (and back???)
    * Can be seen on the wire