A firewall acts as a transparent gateway to a server within a private network by initiating an unsolicited challenge to a client to provide authentication credentials. After receiving the client's credentials, the firewall verifies the authentication credentials and establishes a secure channel for accessing the server. Data destined for the server from the client may be forwarded through the firewall using the secure channel. The firewall may sign, or otherwise indicate that data forwarded to the server is from a client that the firewall has authenticated. The firewall also may provide some level of authentication to the client. While connected to the server, the client may access other servers external to the private network without having the data associated with the other servers pass through the private network. The firewall reduces configuration information that a client otherwise must maintain to access various private network servers.