Skip to main content
phoenix
phoenix
New Member
September 25, 2024
Question

FortiSwitches as a single logical core stack with dynamic routing

  • September 25, 2024
  • 2 replies
  • 1981 views

Is there any way to link two FortiSwitches together so that they can be managed as a single logical unit?.

 

All I can find are options to direct manage to each switch IP, FortiGate Fortilink (but still each switch) or FortiManager.

 

What i'm looking for is a similar way Cisco do the stackwise virtual so that two switches are a logical unit despite being in different locations. You configure both switches via one IP address and you see all ports listed together.

 

I know you can use MCLAG to create a Layer 2 link between the switches so that other edge stacks can connect to both. But I cannot see how to configure and use both switches as one logical unit. Also it gets more complicated as I need to have the FortiSwitches routing so they will have layer 3 IPs and also do some BGP dynamic routing. For routing, is VRRP the only option here if the switches cannot be setup as a single logical stack?

 

The only way I can see it working is:

2 Core FortiSwitches independantly managed by each switch IP (Core 1 and Core 2).

Both switches routing using VRRP between themselves to host the L3 IPs (Core 1 and Core 2).

Both switches linked using MCLAG (Core 1 and Core 2).

Edge stacks dual link to core (1 link to Core 1 and 1 link to Core 2).

Default gateway for VLANs is core stack L3 IPs (using VRRP).

 

In this setup I still have to configure each FortiSwitch independently rather as one unit.

 

2 replies

ebilcari
Staff
ebilcari
Staff
September 28, 2024

For now FortiSW doesn't support that type of virtualization (2 SWs to appear as one logical unit). The closest you can get is is MCLAG and a FortiGate that manages them in Fortilink like shown in this topology.

Emirjon
    alionsol1
    alionsol1
    New Member
    September 29, 2024

    So, the way you manage the FS from the Gate or FortiManager make stacking kinda old school, other than not having LAG'ed uplinks. Stacking in my mind just causes issues. I have dealt with Cisco, Extreme, Enterasys, Juniper, Arista, Avaya switch stacks. ALL of them have issues when the "master" fails, and the secondary takes over. At Fortinet, they are using STP to block redundant links, so if the top switch uplink goes down for some reason, the bottom switch uplink will come out of blocking. You're not getting a 20 Gbps LAG, but you do have failover. Generally speaking, the failover time for STP on FortiSwitch is fast enough for 90% of all networks. Not saying this is the BEST way, this is just the way Fortinet is handling it.

    Terms & ConditionsAccessibility statement