Internet Protocol Version 6 (IPv6) Parameters

Last Updated

• 2025-12-24

Available Formats

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Next Header Types

Reference

• RFC 8200: Internet Protocol, Version 6 (IPv6) Specification
• RFC 2780: IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers
• RFC 7045: Transmission and Processing of IPv6 Extension Headers

Note

This registry has been closed in favor of the IPv6 Extension Header Types registry, also located at Internet Protocol Version 6 (IPv6) Parameters.

IPv6 Extension Header Types

Registration Procedure(s)

• Standards Action or IESG Approval

Reference

• RFC 2780: IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers
• RFC 5237: IANA Allocation Guidelines for the Protocol Field
• RFC 7045: Transmission and Processing of IPv6 Extension Headers
• RFC 9899: Extensions to the YANG Data Model for Access Control Lists (ACLs)

Note

The "IPv6 Extension Header" field in the Assigned Internet Protocol Numbers registry at 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" 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: Internet Protocol, Version 6 (IPv6) Specification
• RFC 2780: IANA Allocation Guidelines For Values In the Internet Protocol and Related Headers
• RFC 9673: IPv6 Hop-by-Hop Options Processing Procedures

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: Internet Protocol, Version 6 (IPv6) Specification
• RFC 5871: IANA Allocation Guidelines for the IPv6 Routing Header

Note

For Traffic Class related information, please see RFC 2474, RFC 3168, and Differentiated Services Field Codepoints (DSCP).

For IPv6 Router Alert Option Values, please see:

IPv6 Router Alert Option Values

Available Formats

• CSV

RPL-option-TLV

Registration Procedure(s)

• IETF Review

Reference

• RFC 6553: The Routing Protocol for Low-Power and Lossy Networks (RPL) Option for Carrying RPL Information in Data-Plane Datagrams

Available Formats

• CSV

TaggerId Types

Registration Procedure(s)

• IETF Review

Reference

• RFC 6621: Simplified Multicast Forwarding

Available Formats

• CSV

Segment Routing Header Flags

Registration Procedure(s)

• IETF Review

Reference

• RFC 8754: IPv6 Segment Routing Header (SRH)

Available Formats

• CSV

Segment Routing Header TLVs

Registration Procedure(s)

• IETF Review

Reference

• RFC 8754: IPv6 Segment Routing Header (SRH)
• RFC Errata 7081

Note

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

Available Formats

• CSV