This is really up to you. NG Firewall provides four test methods - in each case, Untangle sends out data packets and decides if the WAN is up or down depending on your specified Testing, Timeout and Failure Threshold intervals:
- Ping Test: NG Firewall will ping the specified IP address.
- ARP Test: NG Firewall will ARP for its gateway.
- DNS Test: NG Firewall will make a request to the upstream DNS server.
- HTTP Test: NG Firewall will make a connection to the specified domain name.