Sewer odours inside can suggest a dry trap, cracked vent

http://photohistory.oregonstate.edu/works/half/the-importance-of-regular-plumbing-maintenance

Drain odours inside can suggest a dry trap, cracked vent, or partial blockage; Geelong properties with large trees or older sewer lines might need CCTV evaluations to find invasions and prevent reoccuring scents.