Practice question

Which IPv6 address is designated for documentation and examples?

  1. 198.18.0.0/15
  2. 2001:0db8::32
  3. ::ffff/96
  4. 2002::/16

Answer: B — 2001:0db8::32

Documentation and example addresses in IPv6 come from the 2001:db8::/32 range. This block is reserved specifically for illustrating IPv6 syntax in manuals and teaching materials, so it isn’t used on real networks. The address 2001:0db8::32 fits inside that block because the second 16‑bit group 0db8 is the same value as db8, and the double colon expands to fill the remaining groups, giving 2001:0db8:0000:0000:0000:0000:0000:0032. In other words, it lies within the documented prefix 2001:0db8::/32. The other options map to different purposes: an IPv4 benchmarking space, IPv4-mapped IPv6 addresses, and the 6to4 prefix, none of which are designated for documentation and examples.

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