  In this paper we consider an interaction between the air core modes of hollow
core waveguide microstructures and core cladding boundary walls in various
shapes. The analysis is based on well established models such as the
anti-resonant reflecting optical waveguide model and on the models proposed for
the first time. In particular, we consider the dynamics of light localization
in the polygonalcore cladding boundary wall as dependant on the type of its
discrete rotational symmetry. Based on our findings we analyze the mechanisms
of light localization in the core cladding boundary walls of negative curvature
hollow core microstructured fibers.
