ccna book official

ccna book official.Full-featured client (Fullclient) oSSLVPN provides three modes of remote access on CiscoIOS routers: clientless (clientless), thin client (thinclient) > full client (full client) oASA devices have two modes: clientless (clientless, including clientless and thin client port forwarding) and AnyConnect client (alternative to full-featured tunneling).Clientless Access ModeIn clientless mode, remote users use a Web browser on the client machine to access the internal or corporate network. Clientless does not require special VPN software or applets at the user's desktop. All VPN traffic is transmitted and delivered through a standard Web browser. Since no additional software is required, many support issues are eliminated. Using a clientless connection, it is possible to access all Web-enabled applications as well as some client/server applications, such as corporate intranets, applications with Web interfaces, email, online calendars, and file servers.8.6 Implementing Remote Access VPN 247Not all client/server applications are accessible to SSL clients, however this restricted access is often a perfect choice for business partners or contract workers who should only have access to a restricted set of resources on the organization's network. However, it is not appropriate for employees who need full network access.For example, a vendor partner needs "locked down" access to specific extranet resources and applications. On the other hand, public endpoints often give light access to remote users to access mail applications and web-based applications.Thin Client ModeThin client mode, sometimes called TCP port forwarding, assumes that client applications use TCP to connect to a well-known server and port. In this mode, a remote user downloads a Java applet by clicking a link provided on a portal page. This Java applet acts as a TCP proxy on the client machine for the service configured on the SSLVPN gateway. The Java applet opens a new SSL connection for each client connection. The Java applet makes an HTTP request from the remote user client to the SSL VPN gateway that contains the internalemail server name and port number. The SSLVPN gateway creates a TCP connection to this internal email server and port. Thin client mode is often used as a type of clientless mode and is available in all places that support clientless VPNs. It extends the password functionality of a Web browser to enable remote access to TCP-based applications such as POP3, SMTP, IMAP, Telnet, and SSH.