Talk:IPv6 address

Is 2002::/16 really deprecated?

The section on reserved addresses says:

2002::/16 — This prefix was used for 6to4 addressing (an address from the IPv4 network 192.88.99.0/24 was also used). The 6to4 addressing scheme is deprecated.

While citing RFC 7526. But the RFC clearly says in section 4:

The basic unicast 6to4 mechanism defined in [RFC3056] and the associated 6to4 IPv6 prefix 2002::/16 are not deprecated. The default address selection rules specified in [RFC6724] are not modified.

AFAIU this RFC only deprecates the anycast version of 6to4 and the associated IPv4 prefix:

This document formally deprecates the anycast 6to4 transition mechanism defined in [RFC3068] and the associated anycast IPv4 address 192.88.99.1. It is no longer considered to be a useful service of last resort.

The prefix 192.88.99.0/24 MUST NOT be reassigned for other use except by a future IETF Standards Action. StayFoolish2021 (talk) 07:46, 20 April 2023 (UTC)

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• Ipv6 address leading zeros.svg

You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 09:55, 21 April 2023 (UTC)

SLAAC Interface identifier composition from MAC address is not accurate

The example about converting 48-bit MAC address into 64-bit interface identifier should be clearer. It appropriately describes addition of FF-FE in the middle, but is missing that the universal/local bit (next to lowest in first byte) should be complemented in the (common) case of Ethernet interface. There is a footnote comment stating this, but in my opinion it could be said more clearly (in a single short sentence) in the actual paragraph. RFC 2464 describes this quite clearly and could be referenced here. Pasisar (talk) 08:45, 4 March 2024 (UTC)

Bad math

Moved from User talk:Kvng § Bad math

 – ~Kvng (talk) 15:31, 20 February 2026 (UTC)

https://en.wikipedia.org/w/index.php?title=IPv6_address&oldid=prev&diff=1337299906

3fff::/20 –>
From: 3fff::
To: 3fff:0fff:ffff:ffff:ffff:ffff:ffff:ffff
/20 is not /16

3fff:: =
By hextets:
0011111111111111 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
First 20 bit is:
0011111111111111 0000
Not:
0011111111111111
Your correction is incorrect, not professional. Think again! – kgyt (talk) 00:21, 14 February 2026 (UTC)