The present invention relates to a method and an apparatus for providing internal server. The method comprises: matching relevant information carried by a message exchanged between an internal network and an external network with corresponding relationship information between external characteristic information and internal characteristic information of the internal server configured in a mapping table, wherein the external characteristic information comprises an external address and an external port of the internal server, and the internal characteristic information comprises an internal address and an internal port of the internal server; and processing the message according to a matching result. According to the present invention, WEB server and FTP server in the LAN can be easily provided without occupying too much valid IP addresses, thus, the present invention saves limited public IP addresses resource. Furthermore, the present invention implements port-level support to the internal server, and guarantees the security of network equipments.