A Network Configuration, NETCONF, -protocol-based HELLO message interaction method, comprising: bearing, by a server, its capabilities, first Identification, ID, information allocated to a link established with a client and second ID information configured to represent a change state of information of service modules of the server in a first HELLO message, and sending the first HELLO message to the client; receiving, by the server, an acquisition request sent by the client, the sending of the acquisition request being determined by the client according to the second ID information; and sending, by the server, its information of the service modules to the client according to the acquisition request; wherein before sending, by the server, the first HELLO message, the method comprises receiving, by the server, a link establishment request sent by the client; wherein after receiving, by the server, the link establishment request sent by the client and before receiving, by the server, the acquisition request sent by the client, the method further comprises receiving, by the server, a second HELLO message sent by the client, wherein the second HELLO message comprises capabilities of the client, performing, by the server, negotiation on the capabilities of the client in the second HELLO message and the capabilities supported by the server to acquire common capabilities of the server and the client, and determining that link establishment with the client is completed; wherein determining, by the client according to the second ID information, whether to send the acquisition request to the server comprises: determining to send said acquisition request when the client establishes the link with the server for the first time or when the client has established a link with the server and second ID information stored by the client is different from the second ID information in the first HELLO message; and determining not to send said acquisition request when the client has established the link with the server and the second ID information stored by the client is the same as the second ID information in the first HELLO message. bearing, by a server, its capabilities, first Identification, ID, information allocated to a link established with a client and second ID information configured to represent a change state of information of service modules of the server in a first HELLO message, and sending the first HELLO message to the client; receiving, by the server, an acquisition request sent by the client, the sending of the acquisition request being determined by the client according to the second ID information; and sending, by the server, its information of the service modules to the client according to the acquisition request; wherein before sending, by the server, the first HELLO message, the method comprises receiving, by the server, a link establishment request sent by the client; wherein after receiving, by the server, the link establishment request sent by the client and before receiving, by the server, the acquisition request sent by the client, the method further comprises receiving, by the server, a second HELLO message sent by the client, wherein the second HELLO message comprises capabilities of the client, performing, by the server, negotiation on the capabilities of the client in the second HELLO message and the capabilities supported by the server to acquire common capabilities of the server and the client, and determining that link establishment with the client is completed; wherein determining, by the client according to the second ID information, whether to send the acquisition request to the server comprises: determining to send said acquisition request when the client establishes the link with the server for the first time or when the client has established a link with the server and second ID information stored by the client is different from the second ID information in the first HELLO message; and determining not to send said acquisition request when the client has established the link with the server and the second ID information stored by the client is the same as the second ID information in the first HELLO message. determining to send said acquisition request when the client establishes the link with the server for the first time or when the client has established a link with the server and second ID information stored by the client is different from the second ID information in the first HELLO message; and determining not to send said acquisition request when the client has established the link with the server and the second ID information stored by the client is the same as the second ID information in the first HELLO message.