Watchdogs - NetComm NTC-220 User Manual

Watchdogs

The Ping watchdog page is used to configure the behaviour of the Periodic Ping monitor function.
When configured, the Ping watchdog feature transmits controlled ping packets to 1 or 2 user specific IP addresses.
Should the watchdog not receive responses to the pings, it will reboot the device in a last resort attempt to restore
connectivity.
Please be very careful when considering using this feature in situations where the device is intentionally offline for a
particular reason (e.g. user configured PDP session disconnect, or the Connect on demand feature enabled). This is
because the ping watchdog feature expects to be able to access the internet at all times and will always eventually
reboot the router if access isn't restored by the time the various timers and retries expire.
It is due to the nature of the ping watchdog being a last resort standalone backup mechanism that it will continue
to do its job and reboot the device even when the Connect on demand session is idle, or the PDP context is
disabled by the user. Therefore, it is recommended to disable this feature if Connect on demand is configured, or
if the PDP context will be intentionally disconnected on the occasion.
The feature operates as follows:
a After every "Periodic Ping timer" configured interval, the router sends 3 consecutive pings to the
"First destination address".
b If all 3 pings fail the router sends 3 consecutive pings to the "Second address".
c The router then sends 3 consecutive pings to the "Destination address" and 3 consecutive pings to
the "Second address" every "Retry timer" configured interval.
d If all retry pings in step C above fail then number of time configured in "Fail count", the router
reboots.
e If any ping succeeds, the router returns to step A and does not reboot.
Important – The "Periodic Ping timer" should not be set to a value of less than 300 seconds to allow the router time to reconnect to the
cellular network following a reboot.
To disable the Ping watchdog, set Fail count to 0.
NTC-220 – User Guide
UG01028 v1.2 March 2019
Figure 149 – Ping watchdog settings
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© NetComm Wireless 2019