By default, Automatic monitoring is enabled to detect possible interface failures. This means that the health of all uplink interfaces is monitored by having them contact a specific host on the Internet at an interval of 15 seconds. By default, the monitoring host is the third ping-allowing hop on the route to one of the root DNS servers. However, you can define the hosts for monitoring the server pool yourself. For these hosts you can select another service instead of ping, and modify the monitoring interval and timeout.
The monitoring hosts will then be contacted in certain periods and if none of them is reachable, the uplink connection is regarded as down. Subsequently, the actions defined on the Actions tab will be carried out.
Note – Automatically, the same monitoring settings are used for both uplink monitoring (Uplink Monitoring > Advanced) and uplink balancing (Interfaces > Uplink Balancing).
To use your own hosts for monitoring, do the following:
Unselect the Automatic monitoring checkbox.
The Monitoring hosts box becomes editable.
Add monitoring hosts.
Select or add one or more hosts that you want to use for monitoring instead of random hosts. If an interface is monitored by more than one host, it will only be regarded as dead if all monitoring hosts do not respond in the defined time span. How to add a definition is explained on the Definitions & Users > Network Definitions > Network Definitions page.
Note – If a selected host is bound to an interface, it will only be used to monitor this interface. If a host is not bound to an interface, it will be used to monitor all interfaces. Interfaces not covered by the selected hosts will be monitored by automatic monitoring.
Click the Monitoring Settings icon in the box header to set the monitoring details:
Monitoring type: Select the service protocol for the monitor checks. Select either TCP (TCP Transmission Control Protocol connection establishment), UDP (UDP User Datagram Protocol connection establishment), Ping (ICMP Internet Control Message Protocol Ping), HTTP Host (HTTP Hypertext Transfer Protocol requests), or HTTPS Host (HTTPS Hypertext Transfer Protocol Secure requests) for monitoring. When using UDP a ping request will be sent initially which, if successful, is followed by a UDP packet with a payload of 0. If ping does not succeed or the ICMP port is unreachable, the connection is regarded as down.
Port (only with monitoring types TCP and UDP): Port number the request will be sent to.
URL (optional, only with monitoring types HTTP/S Host): URL to be requested. You can use other ports than the default ports 80 or 443 by adding the port information to the URL, e.g., http://example.domain:8080/index.html. If no URL is entered, the root directory will be requested.
Interval: Enter a time interval in seconds at which the hosts are checked.
Timeout: Enter a maximum time span in seconds for the monitoring hosts to send a response. If all monitoring hosts of an interface do not respond during this time, the interface will be regarded as dead.
Your settings will be saved.