IPv6

see also: NAT

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

You have to specify an interface to ping link-local addresses:

ping -I eno1 fe80::1

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

/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

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: phyks)

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

• 3 ways to ruin your future network with IPv6 ULAs
• ULA is broken (in dual-stack networks)

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.

• Wikipedia article on transition mechanisms
• RFC 6877 – 464xlat NAT64 translation

• 4in6
• Lightweight 4over6
• 6in4
• 6over4
• DS-Lite (usually used as CGNAT)
• 6rd
• 6to4
• NAT64 / DNS64
• Teredo
• SIIT
• MAP

• TSP
• 4rd

• Tunnel broker
• IVI
• TRT
• 464XLAT
• Public 4over6
• ISATAP

• AYIYA
• dIVI

Deprecated

  NAT-PT NAPT-PT

• Common misconceptions about IPv6 security (AP-NIC, 2019)
• IPv6 FAQ (Tailscale, 6/2022)
• The Logic of Bad IPv6 Address Management: What Makes Sense for IPv4 Doesn’t Make Sense for IPv6 (Jeff Doyle, Network World, 2012)
• IPv4 and IPv6 comparison (Tecmint, 2015)
• Just how big is IPv6? - or Where did all those addresses go? (Geoff Huston, 2005)
• Hello IPv6: a minimal tutorial for IPv4 users
• 2001:db8::/32 in the Wild

• 464xlat (RFC 6877) is a kind of NAT mechanism