Technical Tip: Configuring Zero Value for Volume or session based SD-WAN Algorithm

[krajaa]

Description
This article explains how to set 0 value.
In some scenarios, the value needs to be set to 0 for any of SD-WAN Members in Session or Volume based SD-WAN Algorithm.
Even though Zero value is set, FortOS considers it as 1 and therefore traffic may flow via those Interfaces.

Solution
WorkAround:

Use priority settings, if SD-WAN is not required.

Configure higher value in Priority settings for the Interface which won't be used in SD-WAN.

***higher the value, lower the priority***

For Example:

3 wan links (WAN1,WAN2,WAN3) configured in SD-WAN with volume ratio 95,5,0 respectively.
Even though wan3 was not configured with any volume (0 volume), FortOS considers it has 1 therefore traffic with a lower priority will flow via this Interface.

#config system virtual-wan-link
set status enable
set load-balance-mode measured-volume-based
config members
edit 1
set interface "wan1"
set gateway x.x.x.x
set volume-ratio 95
next
edit 2
set interface "wan2"
set gateway y.y.y.y
set volume-ratio 5
next
edit 3
set interface "wan3"
set gateway z.z.z.z
next
end

Configured higher priority for wan3, so that It won’t be used in traffic distribution

#config system virtual-wan-link
config members
edit 1
set priority 1
next
edit 2
set priority 1
next
edit 3
set priority 2
next
end