A communication method and apparatus. A session management function obtains at least one group of first association relationships, where the first association relationship is a correspondence between identification information of domain name system DNS handling information and the DNS handling information. The SMF sends, to an EASDF, the at least one group of first association relationships used for PDU sessions of a plurality of terminal devices, and sends, to the EASDF, a first message corresponding to a first PDU session, where the first information includes first identification information, and the first identification information is identification information of DNS handling information corresponding to the first PDU session. The EASDF receives the first association relationship and the first message, and determines, based on the first association relationship and the first identification information, the DNS handling information corresponding to the first PDU session.