1. Introduction

1. Introduction

A single IPv6 address can be text represented in many ways. Examples are shown below.

2001:db8:0:0:1:0:0:1

2001:0db8:0:0:1:0:0:1

2001:db8::1:0:0:1

2001:db8::0:1:0:0:1

2001:0db8::1:0:0:1

2001:db8:0:0:1::1

2001:db8:0000:0:1::1

2001:DB8:0:0:1::1

All of the above examples represent the same IPv6 address. This flexibility has caused many problems for operators, systems engineers, and customers. The problems are noted in Section 3. A canonical representation format to avoid problems is introduced in Section 4.