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fabscim
fabscim
Visitor III
September 23, 2024
Question

Fortiswitch replacing existing Core Switch

  • September 23, 2024
  • 6 replies
  • 2334 views

Hello,

I wanted to replace our existing Aruba Core Switch with a FortiSwitch 148F.

Currently the Aruba is connected to my Fortigate 100F via an LACP with different VLANS , the VLAN 1 is currently used by the network. Here's the screenshot of the existing conf with the Aruba switch connected to port1 and port2

 

image.png

 

 

 

 

 

I've tried to create a software switch with the Fortilink interface and the LACP but i can't use the LACP for the hd switch.

So i attached the Fortiswitch to the Fortilink in order to preconfigure it but i can't create the same VLANS/Subnet on the Fortilink and the fortigate says that they are already used in the LACP.

So i would like to know how to migrate this, i can't attach the fortiswitch directly to the LACP becouse it is a production environment and i have to minimize downtimes so i wanted to attach the Fortiswitch to the Fortlink, then preconfigure the Switch AND the Fortilink with the existing VLANS (but i can't create those networks...) and then just switch the cables from the LACP to the Fortilink.

Attaching the fortiswitch on the fortilink has created a lot of vlans that i don't really useimage.png

 

I'm doing configurations from a SSL VPN, and when i've attached the switch for the first time i saw that the switch went online with a DHCP IP, but even after creating policy from SSLVPN>Fortilink i couldn't access the switch gui, from the fortigate gui it's a mess to understand .

 

Can you help me figure out how to do it?

 

The documentation is not clear.

 

Thanks

6 replies

WANAccounts
WANAccounts
New Member
September 23, 2024

So this is 2 questions right?

1) How can i pre-config my switch, because it's not letting me preconfig the switch without the switch existing in the fortilink

2) Why can I not jumpbox from my FGT to my FSW

Is this right?

    fabscim
    fabscimAuthor
    Visitor III
    September 24, 2024

    The questions are:

     

    1. How can i have the same situation of the LACP on the Fortilink? I just want to unplug the network from the aruba switch and plug it to the Fortiswitch with everything already configured (i can't configure the same vlans /networks used on the lacp on the fortilink so i can use the fiber ports for the fortiswitch x1 and x2 instead of port1 and port2)
    2. The vlan 1 is used in the network by some production devices, i've seen that the vlan 1 is used also for the fortilink, is this a problem?

    thanks

    ebilcari
    Staff
    ebilcari
    Staff
    September 28, 2024

    When the Fortilink is formed the VLANs (of the trunk) are managed through WiFi & Switch Controller (some VLANs are preconfigured and can be deleted).

    The existing VLANs that are created under the LACP link with Aruba SW are just sub interfaces and should not prevent using the same VLAN ID on the switch controller configuration (fortilink):

     

    vlans-inbterface.PNG

    Emirjon
    snmpguru88
    snmpguru88
    New Member
    February 2, 2025

    Hi fabscim

     

    I am just wondering if you were able to solve this? And if so, how? I am facing the same trouble

    GiorgosM
    GiorgosM
    New Member
    March 8, 2026

    Hello

     

    Has anyone found a solution for this? Any experiences to share?
    I’m facing the same scenario where I need to replace Cisco core switches with FSW.
    Demir25
    Demir25
    New Member
    March 9, 2026

    Hi, 

    is it me or you are complicating it a bit. At this point you just need to enable fortilink on the existing 802.3ad aggregate interface and just change the physical cables. At this point you have an active fortilink ready to recognise the new FortiSwitch. You just need to swap the physical cables to the new switch, of course you need a maintenance window here, otherwise Fortigate will not let you configure the same VLAN IDs with the same IPs. 

    Regards.

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