Yes it is, for a finite number of clocks. Having established from a given clock by pairwise signalling, the round trip light signal time to every other clock, a series of synchronising signals is sent to each specific clock at zero minus [half the round trip time for that clock], upon receipt of which each clock is zeroed. Thus all the clocks in the inertial system are [Einstein] synchronised at zero.
Of course the assumption that the clock be synchronised at half the to-and-fro time is the crucial assumption of Einstein synchronisation that puts the "relativity" into special relativity. The clocks will be "synchronised" only for observers actually in the inertial system concerned.