2 CONFIGURATION
2.1 Configure PPP 1 (ADSL)
This PPP interface should already be configured for use with the ISP. You should confirm that you have a working ADSL connection before proceeding with this configuration.
The PPP 1 interface needs to be configured to be “always on”. The inactivity timer should be set to 0.
Configuration - Interfaces > PPP > PPP 0 - 4 > PPP 1 > Standard
Parameter | Setting | Description |
Always on mode | ON | Configures interface as always on |
Inactivity timeout (s): | 0 | Interface is always connected and active |
Click OK
PPP1 should be configured to generate ICMP requests that the firewall can monitor and use to detect when the ADSL connection has a problem.
It is also necessary to configure a settling time on the interface. The settling time is a parameter that prevents the Digi Transport from using the interface until it has been up for the specified number of seconds. This delay is required so that any ICMP echo requests (used for testing the interface) are not sent so soon after the interface has come up that the ISP drops the reply packet. (ISP routing tables are often not updated within the first few seconds of an interface coming up. Sending packets immediately often causes the reply to these packets to be dropped.)
Configuration - Interfaces > PPP > PPP 0 - 4 > PPP 1 > Advanced
Parameter | Setting | Description | |
Ping request interval | 10 | Send ICMP requests every x seconds | |
Only send PINGs when | YES | Do not send ICMP requests if using cellular | |
interface is in service | |||
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PING IP address | 1.2.3.4 | A public IP address that you can ping to | |
check connectivity via ADSL | |||
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Settling time (*100ms) | 100 | Do not send 1st ping until 10 seconds after | |
interface has come up | |||
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