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ahmed_elmelegy
New Contributor

issue with managed fortiswitches

hello all, i have 6 floors in a company , each floor has 2 or 3 edge switches and each office in the floor has a small tp-link switch (5port) that compine the PCs, and this small switch connected to the edge and all floors connected to two core switches working as MCLAG and all the switches are managed by fortigate.

i have 3 connection connected direct to the fortigate (ADSL , MPLS , Leased Line).

on the fortigate i have configured a vlan for each floor , when i enable these vlans and assign them to each floor i found a big packet loss in the network but when i work with one vlan for all floors all thing work fine with no isuue.

can anyone help with this issue?

8 REPLIES 8
AEK
SuperUser
SuperUser

Hi Ahmed

Is the packet loss inter-VLAN? Is there packet loss intra-VLAN as well?

AEK
AEK
ahmed_elmelegy

Hello AEK

No there is no any packet loss inter vlan

The packet loss when ping from pc to 8.8.8.8 

Another thing i want to know

My design is each edge connected to one peer of the MCLAG not the two.

Can this be the issue or not?

AEK
SuperUser
SuperUser

Hi Ahmed

Can you share the following?

  • A screenshot of your FortiLink config from menu Network > Interface
  • A diagram showing how switches are interconnected and how connected with FGT
  • FortiOS version and FortiSwitch OS versions
AEK
AEK
ahmed_elmelegy

hi AEK,

thanks for your replying its highly appreciated.

sorry i cannot take a screenshot now as the customer isnt available but i put two port on fortigate under fortilink and disable split. and all vlans under it.

regarding to the diagram this is the diagram

WhatsApp Image 2025-03-10 at 5.07.20 PM.jpeg

fortiOS is 7.4.7

FortiswitchOS is 7.4.5

 

AEK

So far seems correct.

Split should be disabled as you did.

If you access switches are 1xx series then you cant connect the last one to the second ToR/Core. So what you did should be correct.

Waiting for the screenshot. But meanwhile, did you use VLAN id 1 for any of the created VLANs?

AEK
AEK
ahmed_elmelegy

but when i search i found that i should connect each edge to the two core that working MCLAG not one only is this correct?

no i didnt use vlan 1

 

AEK

I mean when 1xx are chained you can't connect the last one to the second core. That's because 1xx doesn't support multi-homing when daisy-chained, while higher series support it.

However you can do so if the 1xx is standalone (for redundancy). This one is supported.

AEK
AEK
ahmed_elmelegy

hello AEK,

kindly find the screenshot of fortilink

Screenshot 2025-03-13 at 11-37-21 FortiGate - CIS-HQ-1.png

 one of the fortilink memeber is down as i have unistalled the mclag currently and make all network work on one switch as below

Screenshot 2025-03-13 at 11-39-11 FortiGate - CIS-HQ-1.png

 and again i faced the same issue.

and didnt know the reason for this till now

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