Galactic magnetic field manifests itself through a large variety of physical phenomena. It plays a crucial role in the cosmic ray propagation. Connecting the local and the large-scale Galactic magnetic field might help understanding the ISM physics.In this talk I will review state-of-the-art modeling of the large-scale Galactic magnetic field as inferred from the polarized diffuse emission measured by Planck at radio to sub-mm wavelengths.