You are what your father is, mixed raced individuals should never claim to be from a single race. I welcome half somalis to discover their somali sides but I would never belive them to be somali and frankly most somalis back home agree with me, the ones who haven't been indoctrinated with western ideas of race of course.
The issue, that I and many of us have, is the fact that they are not even permitted to celebrate HALF of their lineage on social media, before being swarmed with 'you're not Somali' comments.