The chain-link mesh is one of several net types used as protection against rockfall, shallow landslides and debris flows. The dynamic impact and the corresponding non-linear barrier response require numerical models. Chain-link meshes show a non-linear anisotropic behaviour caused by the geometry of the wire. Resolving this geometry and its deformation results in a bottleneck of numerical costs. We present a discrete element model which covers the non-linear and anisotropic behaviour of the chain-link mesh, using results from either small-scale quasi-static tension tests or from a detailed mechanical model as material-law input. The mesh stiffness, resistance and failure depend on the inner mesh opening angle and thus on the direction of deformation. This information enters the model through the transformation of the non-linear three dimensional deformation processes into a non-linear material-law, with an interpolated dependency on the inner mesh angle. The model maps the resistance of the mesh against impacting masses and covers the energy absorption and it is capable of predicting the dynamic behaviour of different protection barriers with high accuracy, optimized calculation time and minimized calibration efforts. This is illustrated by high impact energy tests which follow the ETAG027 standard, and also with a rockfall attenuating system.