  We report here on the determination of plasma physical parameters across a
shock driven by a Coronal Mass Ejection using White Light (WL) coronagraphic
images and Radio Dynamic Spectra (RDS). The event analyzed here is the
spectacular eruption that occurred on June 7th 2011, a fast CME followed by the
ejection of columns of chromospheric plasma, part of them falling back to the
solar surface, associated with a M2.5 flare and a type-II radio burst. Images
acquired by the SOHO/LASCO coronagraphs (C2 and C3) were employed to track the
CME-driven shock in the corona between 2-12 R$_\odot$ in an angular interval of
about 110$^\circ$. In these intervals we derived 2-Dimensional (2D) maps of
electron density, shock velocity and shock compression ratio, and we measured
the shock inclination angle with respect to the radial direction. Under
plausible assumptions, these quantities were used to infer 2D maps of shock
Mach number $M_\text{A}$ and strength of coronal magnetic fields at the shock's
heights. We found that in the early phases (2-4 R$_\odot$) the whole shock
surface is super-Alfv\'enic, while later on (i.e. higher up) it becomes
super-Alfvenic only at the nose. This is in agreement with the location for the
source of the observed type-II burst, as inferred from RDS combined with the
shock kinematic and coronal densities derived from WL. For the first time, a
coronal shock is used to derive a 2D map of the coronal magnetic field strength
over a 10 R$_\odot$ altitude and $\sim 110^\circ$ latitude intervals.
