Fortigate connection to Cisco 25G/SFP28

[Floh]

Hello,
we have two Fortigate 1000F run in HA (Active/Passive).
We will Connect to Cisco C9500x they run in SVL. 
The Connection from Fortigate (Fortinet SFP28) to Cisco Switch (Cisco SFP28) not work.
Two Ports are  in Aggregation/Portchannel to the Cisco Stack (4 Cabel Connection)
We Test and have set the Port Speed to 25000full or the FEC disable/cl74 etc.
Not work.


At a Cisco sfp10g and in Fortigate we set the Speed to 10000full the link work.
BTW a Cisco sfp with 1G work with the 25g port by set the speed to 1000full. 


The Cisco SFP28 works to outer Cisco Switch with the same model of SFP28.
We have test this with an outer cisco 9500x with SVL an this dose not work.

Version is on Forti 7.4.7

The Aticel have we Test.
25 Gigabit Ethernet connection between Fo... - Fortinet Community

[dbhavsar]

Good day @Floh ,

- Can you enable FEC on both sides, specifically with cl74-fc-fec? If that helps to bring link up or not.

- Also you can collect following debugs and open up a TAC case for further investigation:
config sys interface
edit <affected-interface>
sh fu | grep speed
end

diagnose hardware deviceinfo nic <affected-interface>

[Floh]

Good day @dbhavsar ,
i have FEC aktivate on both sides.
But i have found the Problem.
On Fortigate side the Media typ was of cr (DAC Cabel)
Wen this change to SR and set fec on boath sides it work.

Edit port25
set speed 25000full
set mediantyp SR
set Forward-error-detection cl74....

on Cisco 9500
interface twe1/0/25
fec cl74

And its work on all Fortigate SFP28 Ports.