Sign inMonitor a domain
2001:1::1/128

2001:1::1/128 is the Port Control Protocol Anycast block.

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

Short answer

IANA lists 2001:1::1/128 as “Port Control Protocol Anycast” (RFC 7723). It is not an ordinary public address.

Block2001:1::1/128
First – last2001:1::1 – 2001:1::1
Sizea /128 (2^0 addresses)
Name in the registryPort Control Protocol Anycast
Defined inRFC 7723
Allocated2015-10
Valid as source / destinationTrue / True
ForwardableTrue
Globally reachableTrue

Want the address websites actually see for you? Open the Truth Check.

Sources

  1. IANA IPv6 Special-Purpose Address Registry (CC0) · checked 26 Oct 2026
  2. RFC 7723