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2001:1::3/128

2001:1::3/128 is the DNS-SD Service Registration Protocol Anycast block.

Last updated 26 Oct 2026 from the IANA IPv6 Special-Purpose Address Registry

Short answer

IANA lists 2001:1::3/128 as “DNS-SD Service Registration Protocol Anycast” (RFC 9665). It is not an ordinary public address.

Block2001:1::3/128
First – last2001:1::3 – 2001:1::3
Sizea /128 (2^0 addresses)
Name in the registryDNS-SD Service Registration Protocol Anycast
Defined inRFC 9665
Allocated2024-04
Valid as source / destinationTrue / True
ForwardableTrue
Globally reachableTrue

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Sources

  1. IANA IPv6 Special-Purpose Address Registry (CC0) · checked 26 Oct 2026
  2. RFC 9665