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WAN Link Health Detection
Load Balancing & Fault Tolerance
WAN IP
Service
Server Pool
Server IP
Detect
Service
Weight
211.21.33.186
TCP@5631
192.168.0.15
ICMP
TCP@5631
211.21.33.186
TCP@5632
192.168.0.15
TCP@5632
TCP@5632
211.21.48.194
TCP@2000-
3000
192.168.0.15
ICMP
TCP@2000-
3000
211.21.48.194
UDP@2000-
3000
192.168.0.15
ICMP
UDP@2000-
3000
WAN Link Health Detection
[WAN Link Health Detection] offers you insight into the health status of WAN links. It allows you to set up specific
health detection criteria against each individual WAN link in network of multiple links. FortiWAN detects the connection
status of the WAN link by sending out ICMP and TCP packets to targets, and determines the connection quality with
data that reports back. [WAN Link Detection] lists a few fields to fulfill. Concerning about detection packets flooding,
FortiWAN determines a WAN link alive without sending detection packets if inbound traffic on the WAN link is
detected. The ICMP and TCP detection packets are sent only if no inbound traffic is detected.
For a single detection via ICMP / TCP packets, FortiWAN sends a ICMP or TCP packet (defineded in "Detection
Protocol") individually to multiple targets (defined in "Ping List / TCP Connect List" and "Number of Hosts Picked out
per Detection") via a WAN link (defined in "WAN Link"). FortiWAN determines the WAN link alive if receiving response
from at least one of those targets in a time period (defined in "Detection timeout in milliseconds"), otherwise this
detection is consider failed (FortiWAN will not judge whether a WAN link is down by just one detection failure). No
matter whether a single detection succeed, FortiWAN continues the detection after seconds (defined in "Detection
Period in Second"). The WAN link is determined as down only if multiple detections fail continually (defined in "Number
of Retries"). WAN link health detection monitors the WAN links status which FortiWAN's Summary, Auto Routing,
Multihoming and Statistics will refer to.
Ignore Inbound Traffic
:
Enable [Ignore Inbound Traffic], FortiWAN will determine
WAN link status only by sending ICMP and TCP packets to
targets, regardless of inbound traffic on the WAN link. Dis-
able [Ignore Inbound Traffic], FortiWAN monitors WAN links
status via the mixture of inbound traffic and ICMP / TCP pack-
ets.
Detection timeout in milliseconds
:
This indicates the timeout period for every single detection in
milliseconds. If no response packets are detected during this
period, the system will consider the detection failed.
WAN Link
:
The WAN link to be configured health detection criteria to.
Configure the WAN links individually by selecting them from
the list.
FortiWAN Handbook
Fortinet Technologies Inc.
169