• # fe80 IPv6 Link Local prefix is 10 bits?

I'm confused as to how the fe80 prefix is 10 bits and not 16.

• @michael-salyers,
The notation you see is standardized so you understand that the significant bits are the 1st 10 bits of 128 bits.
Convert `FE80::` to Binary...
Binary:
`*1111.1110.01*00.0000::`

What you see is = 16bits but the `/10` means that only the `first 10 bits` will remain unchanged...(i.e. `FE8..`). So the range in HEX is the following:

`FE80:0000:0000:0000:0000:0000:0000:0000`
through
`FE8F:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF`

note that the first 10 bits remain unchanged as the last 118 bits do. So `FE80/8 has a range of (2^118) addresses = ~33,230,700,000,000,000,000,000,000,000,000,000,000,000

Cordially,
Ronnie Wong
Edutainer, ITProTV

*if the post above has answered the question, please mark the topic as solved.
**All "answers" and responses are offered "as is" and my opinion. There is no implied support or guarantee by the ITProTV team.

• Thanks for the thorough explanation

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