On Tue, Dec 28, 2021, at 21:05, Mike Fischer wrote:
>> Am 28.12.2021 um 13:09 schrieb Paul de Weerd <[email protected]>:
>> Seems like the simplest way, especially using the lladdr option.
> Yes, I’ll give that a try.

Ok, I have tried the following:

Remove my current IPv6 configuration from em0:
# ifconfig em0 -inet6
Test the new configuration:
# ifconfig em0 inet6 autoconf eui64 lladdr f2:b6:71:e6:11:7e

This results in:
- The interface em0 has the expected lladr of f2:b6:71:e6:11:7e
- The link local IPv6 address is: fe80::f0b6:71ff:fee6:117e (using the modified 
EUI-64 version of the lladdr) as expected
- The public IPv4 IPs use my current prefix and a random IID, no relation to 
the lladdr: 2001:db8::eb7f:1267:44d0:45a4 (*)
- The ULA addresses behave the same as the public ones, i.e. the IID has not 
relation to the lladdr.

Why is (one of) the public addresses not using the EUI-64 method of generation 
the IID?

I realize that autoconf generates the SOII addresses with random IIDs. But 
shouldn’t the eui64 option also create an IP with the modified EUI-64 as the 
IID?

ifconfig(8) states:
eui64  Fill the interface index (the lowermost 64 bits of an IPv6 address) 
automatically.

Which is kind of a bland statement anyway. It should IMHO reference that a 
modified EUI-64 is used. But it does not say that this is only true for the 
link local address.


If have tried changing the order of the parameters, but it makes no difference:
ifconfig em0 inet6 autoconf lladdr f2:b6:71:e6:11:7e eui64
ifconfig em0 inet6 lladdr f2:b6:71:e6:11:7e eui64 autoconf

I have also tried to do this without the lladdr parameter, same results just 
with a different lladdr.

If I leave out the autoconf parameter I only get a link local address.


*) I have substituted 2001:db8:: for the real public prefix here.


Thanks!

Mike

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