  Recent analyses of the broad spectral energy distributions (SED) of extensive
lobes of local radio-galaxies have confirmed the leptonic origin of their
Fermi/LAT gamma-ray emission, significantly constraining the level of hadronic
contribution. SED of distant (D > 125 Mpc) radio-galaxy lobes are currently
limited to the radio and X-ray bands, hence give no information on the presence
of non-thermal (NT) protons but are adequate to describe the properties of NT
electrons. Modeling lobe radio and X-ray emission in 3C 98, Pictor A, DA 240,
Cygnus A, 3C 326, and 3C 236, we fully determine the properties of intra-lobe
NT electrons and estimate the level of the related gamma-ray emission from
Compton scattering of the electrons off the superposed Cosmic Microwave
Background, Extragalactic Background Light, and source-specific radiation
fields.
