eth_addr_add(9)

✨ eth_addr_add(9) ✨

okay so bestie, this one's from the Kernel API Manual and it's genuinely so simple you're gonna scream. it's eth_addr_add, and yes before you ask, it does exactly what it says on the tin 💅

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🌸 NAME 🌸

eth_addr_add — Add (or subtract) an offset to/from the given MAC address.

like... math but make it networking 🦋

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✨ SYNOPSIS ✨

void eth_addr_add (u8 *addr , long offset );

no return value, it just does the thing. main character energy fr 🔥

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💖 ARGUMENTS 💖

• addr — Pointer to a six-byte array containing the Ethernet address to increment. six bytes, bestie, that's a MAC address, don't get cute and pass something else 🙈
• offset — Offset to add. and yeah the title says "or subtract" — that's because it's a long, so you can just hand it a negative number and it'll happily go the other way 🎀

ngl the long type on the offset is doing a lot of heavy lifting here — that's the whole trick for going backwards, so don't overthink it 👑

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💜 SEE ALSO 💜

all the siblings live in the Kernel file ./include/linux/etherdevice.h and honestly it's a whole family reunion in there, so let's give everyone a shoutout 🫶

• is_link_local_ether_addr(9)
• is_zero_ether_addr(9)
• is_multicast_ether_addr(9)
• is_local_ether_addr(9)
• is_broadcast_ether_addr(9)
• is_unicast_ether_addr(9)
• is_valid_ether_addr(9)
• eth_proto_is_802_3(9)
• eth_random_addr(9)
• eth_broadcast_addr(9)
• eth_zero_addr(9)
• eth_hw_addr_random(9)
• eth_hw_addr_crc(9)
• ether_addr_copy(9)
• eth_hw_addr_set(9)
• eth_hw_addr_inherit(9)
• ether_addr_equal(9)
• ether_addr_equal_64bits(9)
• ether_addr_equal_unaligned(9)
• ether_addr_equal_masked(9)
• ether_addr_to_u64(9)
• u64_to_ether_addr(9)
• eth_addr_dec(9)
• eth_addr_inc(9)
• is_etherdev_addr(9)
• compare_ether_header(9)
• eth_hw_addr_gen(9)
• eth_skb_pkt_type(9)
• eth_skb_pad(9)

like that's 29 friends and every single one of them is invited to the group chat, iykyk 💀

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and that's the whole page!! short, sweet, and iconic — it lives in ./include/linux, dated October 2026, so go forth and increment (or decrement, we don't judge) your MAC addresses, bestie 🌈⭐💖