About interface id in aggregatable global unicast address

[Yann-Ju Chu]

I have one question about aggregatable global unicast address:

In the format, there is one "Interface ID" field, which is 64-bit long.
I think the length is too long and waste address space. (The field make
the network part of IPv6 address to less than 64 bits)
Since the requirement of
the field is to make the interface on a link unique, why we use other
method, such
as EUI-48 only (only as an example), for the field?


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      Yann-Ju Chu
    Telecommunication Laboratories
    ChungHwa Telecom Co., Ltd.
    TEL: +886 3 424-5681
    FAX: +886 3 424-4888
    http://www.chttl.com.tw
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