Number of Tier supported - MC-LAG

[Bistrol]

Hi the community,

I'm starting to deploy a lot of Fortiswitch for a new project.

All switches will be managed by FGT 1000F.

Tier-1 is composed by 2 FS-1048E (MC-LAG ICL between them).

Tier-2 is composed by 2 FS-548D (MC-LAG ICL between them).

Tier-3 is composed by sometimes FS448 chained using STP, sometimes with FS448 with MC-LAG ICL, ...

All is working as desired in Tier-1 and Tier-2.

But impossible to have communication on a device connected on a switch in tier-3. If i configure these switch to Tier-1, communication works good.

All switches are running 7.2.3.

Is there some limitations on the number of MC-LAG i can configure in the design ?

Regards,

Simon

[Anthony_E]

Hello Simon,

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Thanks,

[Anthony_E]

Hello Simon,

I have found this reddit discussion:

https://www.reddit.com/r/fortinet/comments/w4afd5/mclag_of_3_or_more_fortiswitches/

and this docs document:

https://docs.fortinet.com/document/fortiswitch/6.4.2/devices-managed-by-fortios/617590/mclag-configu...

Could you please tell me if it answers your question?

Regards,

[Bistrol]

Hi Anthony,

Unfortunately, this discussion doesn't answer my question.

The fact here is that a switch in Tier-4 is well recognized and visible in the Fortigate, but communication on its ports doesn't work.

If i plug this switch in Tier-2, all is working fine...

I attach a printscreen of my deployment.

Thanks in advance for any help,

Simon

Simon

[ebilcari]

Basically the tier will not block the communication on the ports. Maybe there is something in the configurations of the 40GB ports. Did you try with normal (non Q) ports? 

[Robbiem77]

Did you ever get to the bottom of this issue you were having? I am designing a network which will pretty much replicate what you have here but with 448E switches but I've never created 4 tier FortiLink solution. Maximum I have done is 3 so am hoping there is not a limit?