An automatic tunnel configuration method using a router advertisement message is provided, including: periodically receiving a router advertisement message containing a tunnel end-point address option from an access router of an internet protocol version 6 (IPv6) network when a mobile node moves from a home network to other IPv6 networks; automatically configuring a tunnel using an address allocated from the access router of the IPv6 network to which the mobile node connects, and the tunnel end-point address option included in the router advertisement message when the network to which the mobile node moves to connect is an internet protocol version 4 (IPv4) network; and communicating with a correspondent node via the configured tunnel using a mobile internet protocol (MIP6).