To bootstrap a DU4 non-global zone you need to edit /etc/apt/sourses.list and copy sources below (do not forget to make the backup of original sourses.list of global zone: sudo cp /etc/apt/sourses.list /etc/apt/sourses.list.orig):
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Bold part is share region between zones.
IP value shall be unique for each zone.
Do not forget to revert the changes in the sources.list file when a non-global zone has been installed (sudo cp /etc/apt/sourses.list.orig /etc/apt/sourses.list).