MAC Address (Cisco Dot-Separated) Regex for Go

What this pattern does

This page provides a well-structured, multi-part regular expression for matching mac address (cisco dot-separated), 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

// MAC Address (Cisco Dot-Separated)
// ReDoS-safe | RegexVault — Web & Network > MAC Address

package validation

import "regexp"

var macAddressCiscoDotseparatedRe = regexp.MustCompile(`^[0-9a-fA-F]{4}\.[0-9a-fA-F]{4}\.[0-9a-fA-F]{4}$`)

func ValidateMacAddressCiscoDotseparated(s string) bool {
    return macAddressCiscoDotseparatedRe.MatchString(s)
}

// Example
// fmt.Println(ValidateMacAddressCiscoDotseparated("001a.2b3c.4d5e")) // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > MAC Address 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

Cisco IOS, Catalyst switches, and Wireshark commonly use this format. The same 48 bits are encoded as 3x4 hex digits rather than 6x2.