An apparatus for establishing a connection in a load-balancing system, the apparatus being coupled between a client device and a real server that provides service to the client device, the apparatus comprising: a memory device storing instructions; and a processor arranged to execute the instructions stored in the memory device to cause the apparatus to: receive a synchronous, SYN, packet from the client device, the SYN packet including client connection information; based on the client connection information, compute a serial number preserving the client connection information; assign the serial number to a first synchronous acknowledgement, SYN+ACK, packet to preserve the client connection information; acquire connection information of the real server through negotiation with the real server; add the acquired connection information of the real server to the first SYN+ACK packet; after adding the acquired connection information of the real server, return the first SYN+ACK packet to the client device; receive an acknowledgement, ACK, packet from the client device and compute to obtain the client connection information based on a confirmation number of the ACK packet; generate a self-defined packet to include the client connection information; and forward the self-defined packet to the real server so that the real server extracts the client connection information from the self-defined packet and establishes a Transmission Control Protocol, TCP, connection with the client device based on the client connection information. a memory device storing instructions; and a processor arranged to execute the instructions stored in the memory device to cause the apparatus to: receive a synchronous, SYN, packet from the client device, the SYN packet including client connection information; based on the client connection information, compute a serial number preserving the client connection information; assign the serial number to a first synchronous acknowledgement, SYN+ACK, packet to preserve the client connection information; acquire connection information of the real server through negotiation with the real server; add the acquired connection information of the real server to the first SYN+ACK packet; after adding the acquired connection information of the real server, return the first SYN+ACK packet to the client device; receive an acknowledgement, ACK, packet from the client device and compute to obtain the client connection information based on a confirmation number of the ACK packet; generate a self-defined packet to include the client connection information; and forward the self-defined packet to the real server so that the real server extracts the client connection information from the self-defined packet and establishes a Transmission Control Protocol, TCP, connection with the client device based on the client connection information. receive a synchronous, SYN, packet from the client device, the SYN packet including client connection information; based on the client connection information, compute a serial number preserving the client connection information; assign the serial number to a first synchronous acknowledgement, SYN+ACK, packet to preserve the client connection information; acquire connection information of the real server through negotiation with the real server; add the acquired connection information of the real server to the first SYN+ACK packet; after adding the acquired connection information of the real server, return the first SYN+ACK packet to the client device; receive an acknowledgement, ACK, packet from the client device and compute to obtain the client connection information based on a confirmation number of the ACK packet; generate a self-defined packet to include the client connection information; and forward the self-defined packet to the real server so that the real server extracts the client connection information from the self-defined packet and establishes a Transmission Control Protocol, TCP, connection with the client device based on the client connection information.