NETGEAR UTM25EW-100NAS Load-Balancing Mode, Table C-9. System Logs WAN Status, Load Balancing

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System Logs: WAN Status, Auto Rollover (continued)

Explanation	The logs suggest that the fail-over was detected after five attempts instead of
	three. However, the reason the messages appear as above is because of the
	WAN state transition logic which is part of the failover algorithm. The above
	logs can be interpreted as below. The primary link failure is properly detected
	after the 3rd attempt. Thereafter the algorithm attempts to restart WAN and
	checks once again to see if WAN1 is still down. This results in the 4th failure
	detection message. If it is then it starts secondary link and once secondary link
	is up, secondary link is marked as active. Meanwhile secondary link has failed
	once more and that results 5th failure detection message. Note that the 5th
	failure detection and the message suggesting that the secondary link is active
	have the same timestamp and so they happen in the same algorithm state-
	machine cycle. So, although it appears that the failover did not happen
	immediately after three failures, internally, the failover process is triggered after
	the 3rd failure and transition to secondary link is completed by the 5th failure.
	The primary link is also restarted every three failures till it is functional again. In
	the above log, primary link was restarted after the 6th failure, that is, three
	failures after the failover process was triggered.
Recommended Action	Check the WAN settings and WAN failure detection method configured for the
	primary link.

Load-Balancing Mode

When the WAN mode is configured for load balancing, both the WAN ports are active simultaneously and the traffic is balanced between them. If one WAN link goes down, all the traffic is diverted to the WAN link that is active.

This section describes the logs that are generated when the WAN mode is set to load balancing.

Table C-9. System Logs: WAN Status, Load Balancing

Message 1	Dec 1 12:11:27 [UTM] [wand] [LBFO] Restarting WAN1_
Message 2	Dec 1 12:11:31 [UTM] [wand] [LBFO] Restarting WAN2_
Message 3	Dec 1 12:11:35 [UTM] [wand] [LBFO] WAN1(UP), WAN2(UP)_
Message 4	Dec 1	12:24:12 [UTM] [wand] [LBFO] WAN1(UP), WAN2(DOWN)_
	Dec 1	12:29:43 [UTM] [wand] [LBFO] Restarting WAN2_
	Dec 1	12:29:47 [UTM] [wand] [LBFO] WAN1(UP), WAN2(DOWN)_
Explanation	Message 1 and Message 2 indicate that both the WANs are restarted.
	Message 3: This message shows that both the WANs are up and the traffic is
	balanced between the two WAN interfaces.
	Message 4: This message shows that one of the WAN links is down. At this
	point, all the traffic is directed through the WAN which is up
Recommended Action	None

C-6 System Logs and Error Messages

v1.0, September 2009