Internet Protocol Version 6 (IPv6) Parameters

Last Updated

2025-12-24

Available Formats

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Registries Included Below

• Next Header Types
• IPv6 Extension Header Types
• Destination Options and Hop-by-Hop Options
• Routing Types
• RPL-option-TLV
• TaggerId Types
• Segment Routing Header Flags
• Segment Routing Header TLVs

Next Header Types

Reference

[RFC 8200][RFC 2780][RFC 7045]

Note

This registry has been closed in favor of the IPv6 Extension Header Types 
registry, also located at [IANA registry ipv6-parameters].
    

IPv6 Extension Header Types

Registration Procedure(s)

Standards Action or IESG Approval

Reference

[RFC 2780][RFC 5237][RFC 7045][RFC 9899]

Note

The "IPv6 Extension Header" field in the Assigned Internet Protocol Numbers 
registry at [IANA registry protocol-numbers] should be updated for any 
Protocol Number added to this registry.
    

Note

When a new code is assigned to an IPv6 Extension Header, the next available
free bit in [IPFIX ipv6ExtensionHeaders Bits] is selected for this new
Extension Header. [IPFIX ipv6ExtensionHeaders Bits] is updated accordingly.
Modifications to existing registrations must be mirrored in
[IPFIX ipv6ExtensionHeaders Bits].
    

Note

When this registry is modified, the YANG module "iana-ipv6-ext-types" 
[IANA registry yang-parameters] must be updated as defined in 
[RFC 9899].
    

Available Formats

CSV

Destination Options and Hop-by-Hop Options

Registration Procedure(s)

IESG Approval, IETF Review or Standards Action

Reference

[RFC 8200][RFC 2780][RFC 9673]

Note

From [RFC 8200] IPv6 Option Types are 8-bit values, 
structured as three subfields, are defined in Section 4.2 of 
[RFC 8200].

Each distinct 8-bit Option Type identifies a different option, i.e., the
high-order 3 bits are considered part of the option identification.
However, it is recommended that Option Types be assigned with distinct
values in the "rest" subfield, until and unless that 5-bit space becomes
full.
    

Available Formats

CSV

Routing Types

Registration Procedure(s)

IETF Review or IESG Approval

Reference

[RFC 8200][RFC 5871]

Note

For Traffic Class related information, please see [RFC 2474],[RFC 3168],
and [https://www.iana.org/assignments/dscp-registry].

For IPv6 Router Alert Option Values, please see:
      
[https://www.iana.org/assignments/ipv6-routeralert-values]
    

Available Formats

CSV

RPL-option-TLV

Registration Procedure(s)

IETF Review

Reference

[RFC 6553]

Available Formats

CSV

TaggerId Types

Registration Procedure(s)

IETF Review

Reference

[RFC 6621]

Available Formats

CSV

Segment Routing Header Flags

Registration Procedure(s)

IETF Review

Reference

[RFC 8754]

Available Formats

CSV

Segment Routing Header TLVs

Registration Procedure(s)

IETF Review

Reference

[RFC 8754][RFC Errata 7081]

Note

0-127: TLVs that do not change en route. 
128-255: TLVs that may change en route.
    

Available Formats

CSV

Footnotes

It is only appropriate to use these values in explicitly-configured experiments;
they MUST NOT be shipped as defaults in implementations.  See [RFC 3692] for details.

It is only appropriate to use these values in explicitly-configured
experiments; they MUST NOT be shipped as defaults in implementations.
See [RFC 3692] for details.