Step 1: Compute side lengths using 3D distance formula.
Between \(A(1,0,0)\) and \(B(0,1,0)\):
\[
AB=\sqrt{(1-0)^2+(0-1)^2+(0-0)^2}
=\sqrt{1+1}=\sqrt{2}
\]
Between \(B(0,1,0)\) and \(C(0,0,1)\):
\[
BC=\sqrt{(0-0)^2+(1-0)^2+(0-1)^2}
=\sqrt{1+1}=\sqrt{2}
\]
Between \(C(0,0,1)\) and \(A(1,0,0)\):
\[
CA=\sqrt{(0-1)^2+(0-0)^2+(1-0)^2}
=\sqrt{1+1}=\sqrt{2}
\]
Step 2: Add all sides.
\[
P=AB+BC+CA=\sqrt{2}+\sqrt{2}+\sqrt{2}=3\sqrt{2}
\]
Final Answer:
\[
\boxed{3\sqrt{2}}
\]