Fortigate 1100E - SDWAN and policy route issue

[pacionet]

Hi,

on Fortigate 1100e (7.4.9) we set up an SDWAN like this

We would OpenNMS pinging a public ip (8.8.8.8) through the line of ROUTER1 and another public IP (8.8.4.4) through the line of ROUTER2. So we set up these policy routes:

SOURCE         DESTINATION      GATEWAY

OPENNMS      8.8.8.8                  ROUTER1

OPENNMS      8.8.4.4                  ROUTER2

In static routes we have:

0.0.0.0/0      SDWAN

In SDWAN policy we have the default (selected members by source IP)

When both interfaces WAN1 and WAN2 are up all works, but:

• If we disable WAN2 interface both ping works
• If we disable WAN1 interface both ping not works

when both interface are up, traceroute show that the routes are correct  (the ping towards 8.8.8.8 choose WAN1 , while the pings toward 8.8.4.4 choose WAN2)

Any ideas?

Thanks

[funkylicious]

hi,

do you do NAT on the FGT or on the routers ?

diagnose firewall proute list - shows correctly what you have configured / can you post it ?

[pacionet]

NAT is on the FGT

Policy routes (gateway are masked):

id=1(0x01) dscp_tag=0xfc 0xfc flags=0x0 tos=0x00 tos_mask=0x00 protocol=0 port=src(0->0):dst(0->0) iif=16(port4)
path(1): oif=66(WAN1) gwy=X.Y.W.Z path_last_used=2025-12-05 09:22:33
source wildcard(1): 10.93.233.229/255.255.255.255
destination wildcard(1): 8.8.8.8/255.255.255.255
hit_count=14065 rule_last_used=2025-12-05 09:22:33

id=2(0x02) dscp_tag=0xfc 0xfc flags=0x0 tos=0x00 tos_mask=0x00 protocol=0 port=src(0->0):dst(0->0) iif=16(port4)
path(1): oif=87(WAN2) gwy=A.B.C.D path_last_used=2025-12-05 09:21:54
source wildcard(1): 10.93.233.229/255.255.255.255
destination wildcard(1): 8.8.4.4/255.255.255.255
hit_count=3925 rule_last_used=2025-12-05 09:21:54

Both policy work when both interface are up, but If we deactivated WAN1, both pings not work

[funkylicious]

do you have auxiliary-session enabled? if not, try enabling it and see if it solves the issue.

config system settings
    set auxiliary-session enable
end