IPv4 Special-Purpose Address Space

Created

• 2009-08-19

Last Updated

• 2025-10-09

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IPv4 Special-Purpose Address Space

Registration Procedure(s)

• IETF Review

Reference

• RFC 5736: IANA IPv4 Special Purpose Address Registry
• RFC 6890: Special-Purpose IP Address Registries
• RFC Errata 6404
• RFC 8190: Updates to the Special-Purpose IP Address Registries

Note

The IETF has reserved the address block of 192.0.0.0/24 for use for special purposes relating to protocol assignments. This registry contains the current assignments made by the IETF from this address block.

Address prefixes listed in the Special-Purpose Address Registry are not guaranteed routability in any particular local or global context.

The IPv4 and IPv6 Special-Purpose Address Registries maintain the following information regarding each entry:

• Address Block - A block of IPv4 or IPv6 addresses that has been registered for a special purpose.

• Name - A descriptive name for the special-purpose address block.

• RFC - The RFC through which the special-purpose address block was requested.

• Allocation Date - The date upon which the special-purpose address block was allocated.

• Termination Date - The date upon which the allocation is to be terminated. This field is applicable for limited-use allocations only.

• Source - A boolean value indicating whether an address from the allocated special-purpose address block is valid when used as the source address of an IP datagram that transits two devices.

• Destination - A boolean value indicating whether an address from the allocated special-purpose address block is valid when used as the destination address of an IP datagram that transits two devices.

• Forwardable - A boolean value indicating whether a router may forward an IP datagram whose destination address is drawn from the allocated special-purpose address block between external interfaces.

• Globally Reachable - A boolean value indicating whether an IP datagram whose destination address is drawn from the allocated special-purpose address block is forwardable beyond a specified administrative domain.

• Reserved-by-Protocol - A boolean value indicating whether the special-purpose address block is reserved by IP, itself. This value is "TRUE" if the RFC that created the special-purpose address block requires all compliant IP implementations to behave in a special way when processing packets either to or from addresses contained by the address block.

If the value of "Destination" is FALSE, the values of "Forwardable" and "Globally Reachable" must also be false.

Formerly known as

IANA IPv4 Special-Purpose Address Registry (pursuant to IESG decision)

Available Formats

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