8. IANA Considerations
8. IANA Considerations
This document makes the following registrations in the "Internet Protocol Version 6 (IPv6) Parameters" "Routing Types" subregistry maintained by IANA:
| Value | Description | Reference |
|---|---|---|
| 4 | Segment Routing Header (SRH) | This document |
This document makes the following registrations in the "Type 4 - Parameter Problem" message of the "Internet Control Message Protocol version 6 (ICMPv6) Parameters" registry maintained by IANA:
| Code | Name |
|---|---|
| 4 | SR Upper-layer Header Error |
8.1. Segment Routing Header Flags Registry
This document describes a new IANA-managed registry to identify SRH Flags Bits. The registration procedure is "IETF Review" [RFC8126]. The registry name is "Segment Routing Header Flags". Flags are 8 bits.
8.2. Segment Routing Header TLVs Registry
This document describes a new IANA-managed registry to identify SRH TLVs. The registration procedure is "IETF Review". The registry name is "Segment Routing Header TLVs". A TLV is identified through an unsigned 8-bit codepoint value, with assigned values 0-127 for TLVs that do not change en route and 128-255 for TLVs that may change en route. The following codepoints are defined in this document:
| Value | Description | Reference |
|---|---|---|
| 0 | Pad1 TLV | This document |
| 1 | Reserved | This document |
| 2 | Reserved | This document |
| 3 | Reserved | This document |
| 4 | PadN TLV | This document |
| 5 | HMAC TLV | This document |
| 6 | Reserved | This document |
| 124-126 | Experimentation and Test | This document |
| 127 | Reserved | This document |
| 252-254 | Experimentation and Test | This document |
| 255 | Reserved | This document |
Values 1, 2, 3, and 6 were defined in draft versions of this specification and are Reserved for backwards compatibility with early implementations and should not be reassigned. Values 127 and 255 are Reserved to allow for expansion of the Type field in future specifications, if needed.