IPv6 Compressed Routing Header with Variable Length Addresses
draft-templin-6man-crh-variable-00

Abstract

The IPv6 Routing Header can be used to direct a packet through multiple intermediate IPv6 waypoints toward a final destination. In its simplest form, the routing header includes the full length of each intermediate IPv6 waypoint. This document specifies a method for supporting variable-length compressed IPv6 addresses.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on November 19, 2020.

Copyright Notice

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Table of Contents

• 1. Introduction
• 2. Terminology
• 3. Requirements
• 4. IPv6 Compressed Routing Header with Variable Length Addresses
• 5. IANA Considerations
• 6. Security Considerations
• 7. Acknowledgements
• 8. References
• 8.1. Normative References
• 8.2. Informative References
• Author's Address

1. Introduction

The IPv6 Routing Header [RFC8200] can be used to direct a packet through multiple intermediate IPv6 waypoints toward a final destination. In its simplest form, the routing header includes the full length of each intermediate IPv6 waypoint. This document specifies a method for supporting variable-length compressed IPv6 addresses.

2. Terminology

The terminology in the normative references applies.

3. Requirements

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119][RFC8174] when, and only when, they appear in all capitals, as shown here.

4. IPv6 Compressed Routing Header with Variable Length Addresses

An IPv6 Compressed Routing Header with Variable length addreses is shown in Figure 1:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Next Header  |  Hdr Ext Len  | Routing Type  | Segments Left |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |T|RSV|  Len[0] |  IPv6 Address[0] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[1] |  IPv6 Address[1] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[2] |  IPv6 Address[2] (0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       ...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
       |T|RSV|  Len[N] |  IPv6 Address[N] [0 to 31 bytes)  .....
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

Figure 1: IPv6 Compressed Routing Header with Variable Length Addresses

In this format:[RFC8138].

• Next Header, Hdr Ext Len, Routing Type and Segments Left have the same meaning as for other compressed routing header formats.
• Immediately following are a set of N type/length/value segments as follows:
  • T indicates whether the following IPv6 Address is compressed on the left-side (most significant bits compressed) or right-side (least significant bits compressed).
  • RSV field is reserved for future use.
  • Len[i] indicates how many contiguous bytes of the left/right compressed IPv6 address follow. Len[i] is a 5-bit field to allow for the case that an IPv6 address is accompanied by an additional piece of information, e.g., a transport port number.
  • IPv6 Address[i] is 0 to 31 bits in length, with either left-side or right-side compression applied.

Note that a similar format appears in

5. IANA Considerations

The IANA is instructed to allocate a routing header type value.

6. Security Considerations

Security considerattions are the same as for other compressed routing header types.

7. Acknowledgements

TBD

8. References

8.1. Normative References

8.2. Informative References

Author's Address