NETGEAR ProSafe FVS336Gv2 Reference Manual page 649

ProSAFE Dual WAN Gigabit WAN SSL VPN Firewall FVS336Gv2
becomes active only until the primary link comes back up. The VPN firewall monitors the
status of the primary link using the configured WAN failure detection method.
This section describes the logs generated when the WAN mode is set to auto-rollover.
Table 24. System logs: WAN status, auto-rollover
Message Nov 17 09:59:09 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 1 of 3 times_
Nov 17 09:59:39 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 2 of 3 times_
Nov 17 10:00:09 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 3 of 3 times_
Nov 17 10:01:01 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 4 of 3 times_
Nov 17 10:01:35 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 5 of 3 times_
Nov 17 10:01:35 [FVS336Gv2] [wand] [LBFO] WAN1(DOWN), WAN2(UP),
ACTIVE(WAN2)_
Nov 17 10:02:25 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 6 of 3 times_
Nov 17 10:02:25 [FVS336Gv2] [wand] [LBFO] Restarting WAN1_
Nov 17 10:02:57 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 7 of 3 times_
Nov 17 10:03:27 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 8 of 3 times_
Nov 17 10:03:57 [FVS336Gv2] [wand] [LBFO] WAN1 Test Failed 9 of 3 times_
Nov 17 10:03:57 [FVS336Gv2] [wand] [LBFO] Restarting WAN1_
Explanation The logs suggest that the failover was detected after 5 attempts instead of 3.
However, the reason that the messages appear in the log is because of the WAN
state transition logic, which is part of the failover algorithm. These logs can be
interpreted as follows:
The primary link failure is correctly detected after the third attempt. Thereafter, the
algorithm attempts to restart the WAN connection and checks once again to
determine if WAN1 is still down. This results in the fourth failure detection
message. If it is still down, then it starts a secondary link, and once the secondary
link is up, the secondary link is marked as active. Meanwhile, the primary link has
failed once more, and that results in the fifth failure detection message. Note that
the fifth failure detection message and the message suggesting that the secondary
link is active have the same time stamp, and so they happen in the same algorithm
state–machine cycle. So although it appears that the failover did not happen
immediately after 3 failures, internally, the failover process is triggered after the
third failure, and transition to the secondary link is completed by the fifth failure.
The primary link is also restarted every 3 failures till it is functional again. In these
logs, the primary link was restarted after the sixth failure, that is, 3 failures after the
failover process was triggered.
Recommended action Check the WAN settings and WAN failure detection method configured for the
primary link.
System Logs and Error Messages
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