/usr/lib/libns3-point-to-point-test.so.3 is in libns3-3 3.13+dfsg-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libns3-point-to-point-test.so.3.13
/usr/lib/libns3-point-to-point-test.so.3.13