FortiSwitch Auto-ISL Trunks Best Practice

[Dan_Eng52]

Hi all, 

I hope you're well. 

I Wonder if someone can give me some guidance on the best practice for auto-isl trunks. Once deployed and automatically established, in order to prevent the trunk configuration from being removed is there a way to disable the auto-isl or is it best to manual create the trunks? 

I know with a FortiGate managed switch the "Lockdown ISL" is available which prevents the automatically created ISLs and ICLs from being accidentally deleted but in terms of a standalone deployment is there a similar command or method to achieve this? 

Thanks, 
Dan_Eng52

[dbu]

If there are few links that need to become trunk than best will be manual configuration of those trunks.

 It depends on the management overhead that you will have. 

I am not sure what will happen in this scenario:

-You set the trunk initially with auto-isl . Trunks are established.

-Change the config from auto to manual. Will the actual configuration be teared down or the trunks will remain operable with the auto config they got?

[mr_vaughn]

I have also been looking for a solution on this. 
I am thinking of creating static trunks 802.3ad LACP from Fortigate of 4x1Gb connections, to a single FortiSwitch. 

I tried to created the LACP trunk and profile the port on FSW. The LACP link comes up but I can never get the Fortilink to manage the switch.. It never get and IP address on the sys int on vlan 4094.
the auto ISL on individual ports for a LACP trunk automatically.