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How long is the most common Ethernet MAC address?

The common Ethernet MAC address is 48 bits long.

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  1. 32 bits
  2. 40 bits
  3. 48 bits ✔

Why: Ethernet most commonly identifies interfaces with a 48-bit MAC address. That identifier operates at the link layer, unlike an IP address at the internet or network layer.

Huh, didn't know that: Forty-eight bits equal six octets, often written as six hexadecimal pairs.

The dad joke
The MAC address brought six octets to complete its look.
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References

Answer: 48 bits. Ethernet most commonly identifies interfaces with a 48-bit MAC address. That identifier operates at the link layer, unlike an IP address at the internet or network layer.

  1. RFC 7042: IANA Considerations for IEEE 802 Parameters www.rfc-editor.org/rfc/rfc7042.html
    48-bit MAC "addresses" are the most commonly used Ethernet interface identifiers.
    Checked 2026-10-10.

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