IPv6 Global Unicast Address (2000::/3) Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching ipv6 global unicast address (2000::/3), ported and verified for Go. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Go project — whether you're validating in a Gin handler, a gRPC service, or a command-line tool.

Go Implementation

// IPv6 Global Unicast Address (2000::/3)
// ReDoS-safe | RegexVault — Web & Network > IPv6

package validation

import "regexp"

var ipv6GlobalUnicastAddress20003Re = regexp.MustCompile(`^[23][0-9a-fA-F]{3}(?::[0-9a-fA-F]{1,4}){7}$`)

func ValidateIpv6GlobalUnicastAddress20003(s string) bool {
    return ipv6GlobalUnicastAddress20003Re.MatchString(s)
}

// Example
// fmt.Println(ValidateIpv6GlobalUnicastAddress20003("2001:0db8:85a3:0000:0000:8a2e:0370:7334")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > IPv6 category and carries a ReDoS-safe certification. That matters for Go developers because Go's RE2 engine is inherently safe from catastrophic backtracking, but this pattern has been additionally verified for correctness. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Global unicast addresses are publicly routable. The 2000::/3 block is the current IANA global unicast allocation (covers 2000:: to 3fff::). Only matches fully expanded form — use net-ipv6-02 for compressed forms.