80C UTM No internet access when connecting wan to TL-R470T+ loadbalance router

[Othman_Mohamed]

Hi, I have TL-R470T+ router and i successfully configured it to bond 4 wan connections from same ISP., so the speed is quite nice and all users are able to surf the internet. but when connecting the router to wan port on fortigate 80C UTM the internet comes down even the other wan port in the UTM is up.  is there any special configuration for this issue? 

[Othman_Mohamed]

Dave, Ede and Bob

Thank you guys very much for your efforts

Internet works well in transparent mode. the 80c utm allowed traffic form the load balance everything is working very well 

@Dave

I agree with you about tp-link products but i,m just using it to combine the 4 ADSL lines. I already tested it and it is not bad.   I'm planning to upgrade the UTM to 100D UTM next year so whats your opinion about this?

is there any method to connect 4 wans directly to fortinet UTM to pass up the tp-link unit? 

thank you. 

[KeremE]

This is very old post. I had the same problem. The Fortigate always detected the TP-Link as offline. I decided to check the logs. I saw there were a lot of dropped pings. They were all false positives. I saw that all my ping attemts to see the interface is alive were detected as ping of death attacks and dropped. Once I've removed all the IPS rules from the firewall. Everyting got back to normal. Fortigate started to detect the TPLink TL-R470T+ as online and SD-wan started to work as expected. 

I hope this helps becasue this problem has haunted me for a very long time.