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Karoui1989
Karoui1989
Explorer
June 2, 2025
Question

Configuration : Link aggregate ( x1 et x2 ) to Portchannel cisco Nexus 5624Q

  • June 2, 2025
  • 2 replies
  • 1220 views

Hello experts,

I have configured interfaces x1 and x2 on the FortiGate as an aggregate interface, and on the other side, a Port-Channel on a Cisco Nexus switch.

I am experiencing ping loss from the FortiGate to a specific IP address.

Could you please help me troubleshoot this?

Below is the configuration.



Switch

sw.png

 

 

Firewall:

fw.jpg

2 replies

Karoui1989
Karoui1989Author
Explorer
June 3, 2025

Help Please

ebilcari
Staff
ebilcari
Staff
June 3, 2025

Is the link aggregation not working properly in general or only the communication to a single IP is affected? Are both links up and actively used (check this article)?

If this affects only a specific session, it may be caused by the LAG algorithm as explained in this article, try to change it.

Emirjon
    Karoui1989
    Karoui1989Author
    Explorer
    June 4, 2025

    Thank you for your answer ,
    the link aggregation work , but i have problem only in the communication  to a single IP is affected 
    i see that fortigate use always X2 as a port , so i disabled x2 but with the X1 i still have the same problem 

    Yurisk
    SuperUser
    Yurisk
    SuperUser
    June 4, 2025

    Also pay attention, at least for the FortiGate-200F/201F, 400F/401F, 600F/601F models there is a known issue when traffic crosses from/to 10 Gig interfaces and 1 Gig interfaces, including packet loss. 

    More info here https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-Known-Issue-Decreased-Throughput-when/ta-p/306488 

     

    https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-troubleshoot-low-throughput-for-traffic/ta-p/329879

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