A photonic network includes a plurality of nodes each supporting add and drop of at least Y wavelengths, a plurality of optical links interconnecting the plurality of nodes, the plurality of optical links support up to X wavelengths and Y≦X, an optical routing protocol configured to compute a loop-free path through the plurality of nodes on the plurality of links, the loop-free path is computed for one of the X wavelengths or a group of the X wavelengths using routing constructs adapted to a photonic domain, and optical components at each of the plurality of nodes configured to selectively block at least one of the X wavelengths based on the computed loop-free path. A photonic routing method and photonic node are also disclosed.