FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
lboaventura1990
Article Id 331678
Description This article describes how to create a configuration for FortiGate to decide what is the best (based on SLA targets) SD-WAN member to be used by FortiGuard and Default DNS Systems.
Scope FortiGate.
Solution
  • Configure the system DNS to use 'interface-select-method sdwan'.


config system dns

    set primary 96.45.45.45

    set secondary 96.45.46.46

    set interface-select-method sdwan

end

  • Edit the SLA performance object Default_DNS, adding the SD-WAN members.

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Note: the option 'Update Static Route' is optional, for more information about this option, check the documentation: 

Technical Note: Routing Change and Session Fail-over with SD-WAN

 

  • Create the SD-WAN rule using the Fortinet ISDBs as a destination.
  • In Outgoing Interfaces select the 'Best Quality' option, select the SD-WAN member used on the SLA performance object.
  • In Zone preference, select the zone's SD-WAN members.
  • In the Quality criteria option, select the Latency.

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    image_3.png

FortiGate # diagnose sys sdwan service 1

Service(1): Address Mode(IPV4) flags=0x200 use-shortcut-sla
Gen(1), TOS(0x0/0x0), Protocol(0: 1->65535), Mode(priority), link-cost-factor(latency), link-cost-threshold(10), heath-check(Default_DNS)
Members(2):
1: Seq_num(1 wan-a), alive, latency: 132.625, selected
2: Seq_num(3 wan-b), alive, latency: 123.146, selected
Internet Service(3): Fortinet-DNS(1245187,0,0,0) Fortinet-FortiGuard(1245324,0,0,0) Fortinet-FortiGuard.Secure.DNS(1245454,0,0,0)
Src address(1):
0.0.0.0-255.255.255.255

When the values of the SD-WAN health check exceed the predefined values, the SD-WAN will send the packets to the best link.

FortiGate # diagnose sys sdwan health-check
Health Check(Default_DNS):
Seq(1 wan-a): state(alive), packet-loss(0.000%) latency(334.956), jitter(4.992), bandwidth-up(9999999), bandwidth-dw(9999997), bandwidth-bi(19999996) sla_map=0x0
Seq(3 wan-b:( state(alive), packet-loss(0.000%) latency(124.233), jitter(3.675), bandwidth-up(9999999), bandwidth-dw(9999997), bandwidth-bi(19999996) sla_map=0x1

FortiGate # diagnose firewall proute list
list route policy info(vf=root):

id=2134048769(0x7f330001) vwl_service=1(FortiGuard_DNS) vwl_mbr_seq=3 1 dscp_tag=0xff 0xff flags=0x0 tos=0x00 tos_mask=0x00 protocol=0 sport=0-65535 iif=0(any) dport=1-65535 path(2) oif=12(wan-b) oif=11(wan-a)
source(1): 0.0.0.0-255.255.255.255
destination wildcard(1): 0.0.0.0/0.0.0.0
internet service(3): Fortinet-DNS(1245187,0,0,0) Fortinet-FortiGuard(1245324,0,0,0) Fortinet-FortiGuard.Secure.DNS(1245454,0,0,0)
hit_count=132 last_used=2024-08-08 14:56:33

 

FortiGate # diagnose ip address list | grep index=12
IP=100.77.1.14->100.77.1.14/255.255.255.252 index=12 devname=wan-b