It's appropriate to wonder what external and internal mean, but we could stipulate some things about the interfaces to be more clear: first being that for any thing to be living, it's on a continuum of manifestations that contain all the code necessary to manifest it since the origin of time. A computer does not fit this criteria because it has an edge at which its existence is nothing more than its raw materials, and it doesn't contain the apparatus necessary to reproduce. After some singular initial condition, an organism is manifestation of a code that has always existed. The tree of life is unbroken, even as its flowers bloom and wilt. A computer is manufactured.
Relative to its manifestation, we known almost everything about the design and operation of a computer: because we stipulated its organization. As it was never designed to be conscious, why should we expect it could ever be so?
Compared to life, of which we relatively know almost nothing about life's design and origination, except that not only does it manifest a-priori to our capacity to understand anything, but by definition gives rise to us.
So consciousness of life is just one of myriad, possibly endless mysteries, and our lack of understanding of consciousness is no more unexpected than our lack understanding about the rest of nature.
We may never get to the bottom of the mysteries, but we can order effects, and in this regard we find a clear distinction between ourselves and machines, one being emergent of our wills and the other giving rise to our wills.
From this vantage we avoid confusion even as we must abide enormous uncertainty.