====== IPv6 ======
see also: [[nat|NAT]]

Certification: [[https://ipv6.he.net/certification/]]

===== Ping link-local addresses =====
You have to specify an interface to ping link-local addresses:
<code bash>
ping -I eno1 fe80::1
</code>

===== configuration =====

==== systemd-networkd ====
specify ''[Address]'' and ''[Gateway]'' in ''/etc/systemd/network/50-default.network''. You need a route to your gateway!

<file ini /etc/systemd/network/50-default.network>
[Network]
…
Gateway=2001:41d0:000a:69ff:ff:ff:ff:ff
…
[Address]
Address=2001:41d0:000a:69af::1/128
…
[Route]
Destination=2001:41d0:000a:69ff:ff:ff:ff:ff
Scope=link
</file>

===== Kimsufi =====

  ip -6 addr add YOUR_IPV6_ADDRESS/64 dev eth0

This will add the ipv6 address to your network device. Then, you have to manually add the default gateway. To get its address, you should remove the last two digits of your ipv6 address and put ''FF:FF:FF:FF:FF'' instead. This means that ''2001:41d0:1:4462::1/64'' will give you a default gateway ''2001:41d0:1:44FF:FF:FF:FF:FF''.

Then, you should add a default route via this gateway

  ip -6 r a default via 2001:41d0:1:44FF:FF:FF:FF:FF

This is the standard procedure explained in the OVH guide. It may work in some cases, however, in my case, I could not reach the default gateway and then, I could not add this route.

I found a comment on the OVH forum giving a solution.

You should first add a route to reach the gateway

  ip -6 r a 2001:41d0:1:44FF:FF:FF:FF:FF dev eth0

and then, you can add the default route via this gateway

  ip -6 r a default via 2001:41d0:1:44FF:FF:FF:FF:FF

(Source: [[https://phyks.me/2014/11/getting-ipv6-to-work-with-a-kimsufi-server.html|phyks]])

===== connect with browser =====
Enter ''http://[::1]'' (''::1'' = localhost) in the URL bar.

===== IPv4 Rosetta =====
^ IPv4 ^ IPv6 ^ Meaning |
| 127.0.0.1 | ::1 | localhost |
| 0.0.0.0 | :: | no host |
| 0.0.0.0/0 | ::/0 | all hosts, all networks |

===== Unique Local Addressing (ULA) =====
  * [[https://blogs.infoblox.com/ipv6-coe/3-ways-to-ruin-your-future-network-with-ipv6-unique-local/|3 ways to ruin your future network with IPv6 ULAs]]
  * [[https://blog.apnic.net/2022/05/16/ula-is-broken-in-dual-stack-networks/|ULA is broken (in dual-stack networks)]]

===== Transition mechanisms =====
Since IPv4 and IPv6 are both widely used and IPv4 isn't going away anytime soon, we need translation mechanisms to transition between both technologies.

  * [[https://en.wikipedia.org/wiki/IPv6_transition_mechanism|Wikipedia article on transition mechanisms]]
  * [[https://www.rfc-editor.org/rfc/rfc6877|RFC 6877]] – [[https://en.wikipedia.org/wiki/IPv6_transition_mechanism#464XLAT|464xlat]] NAT64 translation

==== Standards Track ====
  * 4in6
  * Lightweight 4over6
  * 6in4
  * 6over4
  * DS-Lite (usually used as [[admin:network:cgnat|CGNAT]])
  * 6rd
  * 6to4
  * NAT64 / DNS64
  * Teredo
  * SIIT
  * MAP

==== Experimental ====
  * TSP
  * 4rd

==== Informational ====
  * Tunnel broker
  * IVI
  * TRT
  * 464XLAT
  * Public 4over6
  * ISATAP

==== Drafts ====
  * AYIYA
  * dIVI

Deprecated

    NAT-PT NAPT-PT

===== Articles =====
  * [[https://blog.apnic.net/2019/03/18/common-misconceptions-about-ipv6-security/|Common misconceptions about IPv6 security]] (AP-NIC, 2019)
  * [[https://tailscale.com/kb/1134/ipv6-faq/|IPv6 FAQ]] (Tailscale, 6/2022)
  * [[https://www.networkworld.com/article/2223248/the-logic-of-bad-ipv6-address-management.html|The Logic of Bad IPv6 Address Management: What Makes Sense for IPv4 Doesn’t Make Sense for IPv6]] (Jeff Doyle, Network World, 2012)
  * [[https://www.tecmint.com/ipv4-and-ipv6-comparison/|IPv4 and IPv6 comparison]] (Tecmint, 2015)
  * [[https://www.potaroo.net/ispcol/2005-07/ipv6size.html|Just how big is IPv6? - or Where did all those addresses go?]] (Geoff Huston, 2005)
  * [[https://metebalci.com/blog/hello-ipv6/|Hello IPv6: a minimal tutorial for IPv4 users]]
  * [[https://weberblog.net/2001db8-32-in-the-wild/|2001:db8::/32 in the Wild]]

===== Standards =====
  * 464xlat (RFC 6877) is a kind of [[NAT]] mechanism