REGEXVAULTv2.0
Web & Network/MAC Address
Verified Safe

MAC OUI (Organizationally Unique Identifier) Regex for Java

/^[0-9a-fA-F]{2}(?::[0-9a-fA-F]{2}){2}$/

What this pattern does

This page provides a well-structured, multi-part regular expression for matching mac oui (organizationally unique identifier), ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.

Java Implementation

Java
// MAC OUI (Organizationally Unique Identifier)
// ReDoS-safe | RegexVault — Web & Network > MAC Address

import java.util.regex.Pattern;

public class MacOuiOrganizationallyUniqueIdentifierValidator {
    private static final Pattern PATTERN =
        Pattern.compile("^[0-9a-fA-F]{2}(?::[0-9a-fA-F]{2}){2}$");

    public static boolean validate(String input) {
        return PATTERN.matcher(input).matches();
    }

    // Example
    public static void main(String[] args) {
        System.out.println(validate("00:1a:2b")); // true
    }
}

Test Cases

Matches (Valid)
Rejects (Invalid)
00:1a:2b00:1a
FF:FF:FF00:1a:2b:3c
A0:B1:C200:1a:2b:3c:4d:5e
00:50:56GG:HH:II
DC:A6:32001a2b

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 Java developers because critical in Java applications since the JVM regex engine uses backtracking and is susceptible to ReDoS without careful pattern design. 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

Locally administered bits (bit 1 of the first byte) indicate the MAC was not assigned by a manufacturer — check the second-least-significant bit of the first octet.

Technical Notes

00:50:56 is VMware, DC:A6:32 is Raspberry Pi Foundation. OUI lookup databases (IEEE public registry) can identify vendors from this prefix.

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