D-Link DFL-CPG310 Product Manual - Page 99

Using Internet Setup In this field... Do this... Connection Probing Method While the Probe Next Hop option checks the availability of the next hop router, which is usually at your ISP, connectivity to the next hop router does not always indicate that the Internet is accessible. For example, if there is a problem with a different router at the ISP, the next hop will be reachable, but the Internet might be inaccessible. Connection probing is a way to detect Internet failures that are more than one hop away. Specify what method to use for probing the connection, by selecting one of the following: • None. Do not perform Internet connection probing. Next hop probing will still be used, if the Probe Next Hop check box is selected. This is the default value. • Ping Addresses. Ping anywhere from one to three servers specified by IP address or DNS name in the 1, 2, and 3 fields. If for 45 seconds none of the defined servers respond to pinging, the Internet connection is considered to be down. Use this method if you have reliable servers that can be pinged, that are a good indicator of Internet connectivity, and that are not likely to fail simultaneously (that is, they are not at the same location). • Probe DNS Servers. Probe the primary and secondary DNS servers. If for 45 seconds neither gateway responds, the Internet connection is considered to be down. Use this method if the availability of your DNS servers is a good indicator for the availability of Internet connectivity. • Probe VPN Gateway (RDP). Send RDP echo requests to up to three Check Point VPN gateways specified by IP address or DNS name in the 1, 2, and 3 fields. If for 45 seconds none of the defined gateways respond, the Internet connection is considered to be down. Use this option if you have Check Point VPN gateways, and you want loss of connectivity to these gateways to trigger ISP failover to an Internet connection from which these gateways are reachable. Chapter 4: Configuring the Internet Connection 83