The described technology is generally directed towards network slice pre-configuration for cellular communication systems, including 5G and subsequent generation cellular communication systems. Network equipment can be preconfigured to identify whether a network slice identifier included in a network communication belongs to a group of network slice identifiers. If so, the network equipment can process the network communication either according to a network slice rule that corresponds specifically to the network slice identifier, or according to a default group network slice rule for the group to which the network slice identifier belongs. Different groups of network slice identifiers can be associated with different sets of group network slice rules which can be arranged to reduce the work of setting up network slice identifiers in various network slicing scenarios.