The router can monitor network connections and attempt to recover when a high-level communication failure is detected on a WAN or LAN connection. For example, when the router is connected to an Ethernet WAN link but the link stops passing traffic, the router can switch to another available WAN link and restart its Ethernet port in order to attempt to recover connectivity.
The Network Watchdog detects connection failures and recovers the connection by periodically checking against its preconfigured parameters for conditions such as a minimum number of connection failures and timeouts.
The RULES table shows you the configuration and status of each Network Watchdog Monitoring Rule. From the RULES table, you can also configure some of the rule settings:
Select the Monitored Zone(s)
Enable or disable the rule
Turn WAN Policy Link Validation on or off.
For more information, see the table below.
COLUMN | DESCRIPTION |
---|---|
MONITORED ZONE | Zone that is being monitored. Click the field to select a different or additional User Zone, System Zone or Interface |
SUMMARY | Summary of the monitoring rule’s ACTION and METHOD. For example, the summary “per interface restart on smart icmp ping failure” indicates that the interface will restart if the “ICMP ping on idle traffic” monitoring method detects a network failure (“smart” refers to the “idle traffic” element of the monitoring method). See Configuring a Monitoring Rule below. |
ENABLE | Enable or disable the Monitoring Rule |
STATUS |
Current status of the rule
|
WAN POLICY LINK VALIDATION | Enable or disable WAN POLICY LINK VALIDATION. See Configuring a Monitoring Rule below. |
Go to Networking > Network Watchdog > Monitoring Rules.
Click CREATE MONITORING RULE to create a new rule, or click Edit ( ) in the RULES table to update an existing rule.
Begin configuring the Monitoring Rule.
Click the MONITORED ZONE field to choose which Zones (System Zones or your own defined zones) or interfaces you want to monitor. Zones are a group of interfaces. Add as many Monitored Zones as you want.
WARNING : When selecting the MONITORED ZONE, ensure that you do not select an interface or zone that already has a network monitoring rule applied. Multiple networking monitor rules are not supported on the same interface.
Select the ACTION the router will take when the watchdog detects a failure:
per zone restart restarts all interfaces in the monitored zone when all interfaces in the monitored zone are down.
per interface restart restarts an interface in the monitored zone when that interface is down.
per zone reboot reboots the router when all interfaces in the monitored zone are not working.
Select the monitoring METHOD:
idle traffic allows you to monitor without sending a ping. AirLink OS monitors traffic (TX/RX bytes per second) to determine whether the selected interface(s) are operating. This method is suitable for satellite links, where you want to minimize monitoring-related traffic (such as pings or DNS lookups used by other methods).
ICMP ping: sends ping traffic at a configured interval whether the interface is idle or carrying traffic.
ICMP ping on idle traffic: sends a ping when the router detects idle traffic (no increase in RX/TX values is detected).
DNS lookup: attempts to resolve host names at a configured interval whether the interface is Idle or carrying traffic.
DNS lookup on idle traffic tries to resolve the hostname when traffic is considered idle. Some firewalls do not allow ICMP pings through, so DNS lookup is the best option in that case.
Select the INTERVAL. Depending on the monitoring method you’ve selected, the interval determines:
How often a ping is sent. Frequent pings are used especially for Wi-Fi links.
How often the router checks TX/RX bytes to determine if traffic is idle.
Select the MAX FAILURES (from 1 to 10) to set the number of successive failures (failed pings or idle traffic detected, depending on your monitoring method) before the router takes the specified action.
For monitoring methods other than idle traffic, set the following fields (both fields accept hostname [FQDN] or IPv4 or IPv6 address):
Primary Host
Secondary Host (optional, used if the Primary Host fails)
Primary Host and Secondary Host are used to do ping and DNS resolution when an active method is chosen.
Enable or disable WAN POLICY LINK VALIDATION. This setting is not directly related to the Network Watchdog, but it is used in Multi-WAN Policy as an additional check to determine whether a WAN link/interface can reach a DNS server (the Primary Host or Secondary Host you have configured) and be considered a usable link by any of the Multi-WAN policies. In some situations, a WAN link comes up and connects but it can’t pass traffic due to the lack of DNS. When WAN POLICY LINK VALIDATION is enabled, the router sends pings or DNS requests to validate the link. You can leave this setting disabled if the router uses only a single WAN link.
If WAN Policy Link Validation is enabled, set the following fields (both fields accept hostname [FQDN] or IPv4 or IPv6 address):
Primary Host
Secondary Host (optional, used if the Primary Host fails)
Primary Host and Secondary Host are used to do ping and DNS resolution when WAN Policy Link Validation is enabled.
Click CREATE.
If you are using your router in a non-cellular application, ensure that you disable the router’s cellular interface(s) under Hardware Interfaces > Cellular Interfaces > Configuration. Note that the Network Watchdog is preconfigured to restart the WAN zone after an ICMP ping detects a failure. Because the default WAN zone includes the Cellular interface, a device without a SIM card will restart its cellular interface continuously. Do not disable the Cellular LPWA interface, because this will affect the connection to ALMS and your ability to remotely configure the router.