Packet processing rule versioning

Some embodiments provide a method for a managed forwarding element that processes packets through a set of packet processing tables by matching rules in the tables. The method receives an update that requires modification to at least one of the packet processing tables. Each rule in the packet processing tables is assigned a range of packet processing table versions in which the rule is valid for processing packets. The method modifies the packet processing tables according to the received update by at least one of (i) modifying the range of packet processing table versions in which an existing rule is valid to end after a current packet processing table version and (ii) adding a new rule with a range of valid packet processing table versions that begins with a next packet processing table version. The method increments the current version of the packet processing tables to commit the modifications.