IPv6 Subnet Calculator + EUI-64 / SLAAC Helper

Input

IPv6 Address / CIDR

Prefix length

Split to new prefix

Tips: use :: shorthand, or full 8 hextets. Zone IDs (like %eth0) aren’t supported.

Expanded

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Compressed

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Prefix

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Network

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First address

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Last address

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Host bits

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Total addresses

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Page size

Jump to Nth subnet (0-based)

Index	Subnet CIDR	Range (first → last)
No subnets to show yet. Click “Split”.

If the split creates too many subnets, paging + “Nth subnet” lets you navigate without listing them all.

MAC address

IPv6 /64 prefix

Modified EUI-64 IID

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IID (hextets)

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SLAAC address

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Recovered MAC

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Notes: SLAAC with EUI-64 flips the MAC’s U/L bit and inserts ff:fe in the middle. Many modern systems use privacy IIDs instead.