Fernando Gont wrote:
> The specific 128-bit value seems to be a compromise between two
> proposals
>
(https://www.lacnic.net/innovaportal/file/2578/1/ipv6-latnic2018-hinden-01.pdf)...
> but I won't speak for Bob. ;-)
That is an inappropriate explanation. As variable length address
is not adopted, among three reasons for TUBA on slide 13:
Compatible with OSI NSAP address plans
Large enough for auto-configuration using IEEE 802 addresses
Could start with short addresses and grow later
only
Large enough for auto-configuration using IEEE 802 addresses
remains.
That is, IPv6 address unnecessarily became 128bit long, merely
because of poor idea of so stateful SLAAC.
Phillip Hallam-Baker wrote:
>> e) 64 isn't enough to allow lots of bits for topology plus
>> lots of bits for privacy
is a typical misunderstanding by those who do not know 32 bit
IPv4 address is enough to represent hierarchical topology of
the Internet today.
>The reason we went to 128 bits was 64+64 = 128
It was assumed that networks would want to map MAC addresses onto the lower
bits of the address and those were already in the process of expanding to
64 bits.
No, the reason is because I pointed out that MAC address of IEEE1394
is already 64bit long. Before that, it was 80+48.
This hasn't happened because it is nonsense. Disclosing the
structure of your internal network to potential attackers is stupid.
Wrong.
Extending MAC address 64 bit has nothing to do with internal topology.
Masataka Ohta
