  We present our analysis of UV attenuation by internal dust of a large sample
(N=906 galaxies) of Lyman Break Galaxies (LBGs). Using spectral energy
distributions (SEDs) from the P\'EGASE galaxy spectral evolution model we apply
dust attenuation corrections to the G-R colors using the Witt & Gordon (2000)
models for radiative transfer in dusty galactic environments to arrive at the
UV attenuation factors. We show that the dust in the LBGs exhibit SMC-like
characteristics rather than MW-like, and that the dust geometry in these
systems is most likely to be represented by a clumpy shell configuration. We
show that the attenuation factor exhibits a pronounced dependence on the
luminosity of the LBG, $a_{1600}\propto (L/L_\sun)^\alpha$, where
$0.5\leq\alpha\leq1.5$. The exponent $\alpha$ depends on the initial parameters
of the stellar population chosen to model the galaxies and the dust properties.
We find that the luminosity weighted average attenuation factor is likely to be
in the range from $5.7-18.5$, which is consistent with the upper limits to the
star formation rate at $2<z<4$ set by the FIR background. This implies that the
current UV/optical surveys do detect the bulk of the star formation during the
epoch $2<z<4$, but require substantial correction for internal dust
attenuation.
