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sean3
Explorer II
March 12, 2025
Solved

why the traffic is following the SD-WAN rule in this case?

  • March 12, 2025
  • 2 replies
  • 1048 views

greetings friend,

I created an IPsec tunnel named OL_INET_AZ, and it was added to an SD-WAN zone. but there is NO SD-WAN rule using this IPsec tunnel as the outgoing interface.

 

there are 3 static routes:

S 10.74.0.0/15 [10/0] via 1.2.3.4, port17, [1/0]
                        [10/0] via OL_INET_SKO tunnel a.b.c.d, [20/0]
S 10.75.0.0/23 [10/0] via OL_INET_AZ tunnel v.w.x.y, [1/0]

Now my LAN network want to talk to 10.75.1.68 via OL_INET_AZ.  From the routing table 10.75.0.0/23 via OL_INET_AZ is the best route as it is most specific. When I ping 10.75.1.68 from the fortigate itself, the traffic is going through OL_INET_AZ, but if I ping from a LAN host behind the Fortigate (and behind the core switch) , it will hit the SD-WAN rule with destination 10.74.0.0/15, and going through port17.

From SD-WAN routing logic, it said SD-WAN rules are matched only if the best route to the destination points to SD-WAN, will this rule be applicable even though the Ipsec tunnel is not used by any SD-WAN rule (but added to SD-WAN zone) ?

 

If I want to achieve my goal that the traffic to 10.75.1.68 go through OL_INET_AZ, I need to either:

  1. remove the OL_INET_AZ from SD-WAN zone, to make it a non SD-WAN member interface, or
  2. create sd-wan rule for 10.75.0.0/23, add OL_INET_AZ as the outgoing interface for this rule

am I right?

Thanks

    Best answer by sean3

    Thanks for the reply.

    I've configured the sd-wan rule with Manual strategy using that IPSec tunnel, which works as expected. I just want to confirm that, though the ipsec tunnel is not using by any sd-wan rule but added to sd-wan zone, the SD-WAN will anyway take precedence for traffic routing if it meets the requirement of SD-WAN routing logic, could you please help to confirm?

     

    thanks

    2 replies

    Shashwati
    Staff
    Staff
    March 12, 2025

    Hello , 

    Please first confirm that you have Firewall policy configured to allow LAN users to connect to the specific subnet suing Tunnel . You can also try configuring SDWAN rule to forward traffic to the Tunnel 

    sean3
    sean3AuthorAnswer
    Explorer II
    March 13, 2025

    Thanks for the reply.

    I've configured the sd-wan rule with Manual strategy using that IPSec tunnel, which works as expected. I just want to confirm that, though the ipsec tunnel is not using by any sd-wan rule but added to sd-wan zone, the SD-WAN will anyway take precedence for traffic routing if it meets the requirement of SD-WAN routing logic, could you please help to confirm?

     

    thanks

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