Netgear SRX5308 SRX5308 Reference Manual - Page 122

ProSafe Gigabit Quad WAN SSL VPN Firewall SRX5308 Reference Manual For example, Web servers serve Web pages, time servers serve time and date information, and game hosts serve data about other players' moves. When a computer on the Internet sends a request for service to a server computer, the requested service is identified by a service or port number. This number appears as the destination port number in the transmitted IP packets. For example, a packet that is sent with destination port number 80 is an HTTP (Web server) request. The service numbers for many common protocols are defined by the Internet Engineering Task Force (IETF) and published in RFC 1700, "Assigned Numbers." Service numbers for other applications are typically chosen from the range 1024 to 65535 by the authors of the application. Although the VPN firewall already holds a list of many service port numbers, you are not limited to these choices. Use the Services screen to add additional services and applications to the list for use in defining firewall rules. The Services screen shows a list of services that you have defined, as shown in Figure 4-19. To define a new service, first you must determine which port number or range of numbers is used by the application. This information can usually be determined by contacting the publisher of the application or from user groups of newsgroups. When you have the port number information, you can enter it on the Services screen. To add a customized service: 1. Select Security > Services from the menu. The Services submenu tabs display, with the Services screen in view. The screen displays the Custom Services Table with the user-defined services. (Figure 4-19 shows some examples.) Figure 4-19 4-32 v1.0, April 2010 Firewall Protection