A relaying system and method of transmitting an IP address of a client to a server by using an encapsulation protocol are provided. The relaying system includes: a first proxy configured to receive an original packet including the IP address of the client in a header of the original packet attach the original packet to the inside of an encapsulation packet consisting of a header and a payload by using a predetermined encapsulation protocol, and generate a reconstructed packet; and at least one second proxy or bridge router configured to extract the original packet attached to the inside of the encapsulation packet and transmit information about the IP address of the client to the server. According to the relaying system and method, a host server is able to provide services using information in a packet header such as an IP address of a terminal. The presence of a proxy may be not shown to the client and the server. Tunneling communication is enabled between two terminals without any specific changes to a terminal and a host server or installation of a specific program. Furthermore, use of an encapsulation protocol is advantageous for security, and it is possible to quickly find an encapsulation packet.