  Baryon and lepton numbers being accidental global symmetries of the Standard
Model (SM), it is natural to promote them to local symmetries. However, to
preserve anomaly freedom, only combinations of B-L are viable. In this spirit,
we investigate possible dark matter realizations in the context of the
$U(1)_{B-L}$ model: (i) Dirac fermion with unbroken B-L; (ii) Dirac fermion
with broken B-L; (iii) scalar dark matter; (iv) two component dark matter. We
compute the relic abundance, direct and indirect detection observables and
confront them with recent results from Planck, LUX-2016, and Fermi-LAT and
prospects from XENON1T. In addition to the well known LEP bound
$M_{Z^{\prime}}/g_{BL} \gtrsim 7$ TeV, we include often ignored LHC bounds
using 13 TeV dilepton (dimuon+dielectron) data at next-to-leading order plus
next-to-leading logarithmic accuracy. We show that, for gauge couplings smaller
than $0.4$, the LHC gives rise to the strongest collider limit. In particular,
we find $M_{Z^{\prime}}/g_{BL} > 8.7$ TeV for $g_{BL}=0.3$. We conclude that
the NLO+NLL corrections improve the dilepton bounds on the $Z^{\prime}$ mass
and that both dark matter candidates are only viable in the $Z^{\prime}$
resonance region, with the parameter space for scalar dark matter being fully
probed by XENON1T. Lastly, we show that one can successfully have a minimal two
component dark matter model.
