  We study the magnetic response of mesoscopic metallic isolated networks. We
calculate the average and typical magnetizations in the diffusive regime for
non-interacting electrons or in the first order Hartree-Fock approximation.
These quantities are related to the return probability for a diffusive particle
on the corresponding network. By solution of the diffusion equation on various
types of networks, including a ring with arms or an infinite square network, we
deduce the corresponding magnetizations. In the case of an infinite network,
the Hartree-Fock average magnetization stays finite in the thermodynamic limit.
