From the Posted Sales Shipment page you can check to see if a Consignment already exists for this Sales Shipment. You do this by selecting the Related > Consignment >Consignment Lines from the action bar.
If there are no Consignment Lines shown, then it indicates that the Posted Sales Shipment has not yet been consigned. You can manually create one by selecting the Create Consignment Function from the Posted Sales Shipment Page.
If the Posted Sales Shipment relates to an export order where Container Tracking Entries exist, if you change the No. of Packages prior to creating the Consignment and Auto Create Containers has been setup against the Shipping Agent Service assigned to the shipment, the system will re-generate the Container Tracking based on the updated No. of Packages according to the auto creation functionality detailed here.