Add VLAN sub interfaces to a fisical interface

[hgg]

Hi

Right now i have a network in production with no VLANS, a change in circunstances force me to create several VLANS to better segment our network and improve our security.

My question is:

Can i add VLAN Sub interfaces to our, currently in production, VLANless physical interface without consequences or should i create a new interface for the previous physical interface (for example as VLAN 1 or native) beside the new ones with the issues this will bring (DHCP among others)?

Thank in advance

[hgg]

Thanks sw2090

But i have a question.

When you say "So better use something else on your FGT to create virtual vlan interfaces.", what do you mean?

My problem is i have a lot of devices i need to move to the VLANS without thenm stop working, so they will stay in the current VLAN until i move them in an orderly fashion to their proper VLANs.

I have a physical interface where all my network arrives right now, what worries me is that in a Cisco enviroment the root interface can not have IP address, only the sub interfaces. What i understand from your answer and from others who answered this post is that i can create a VLAN Interface over this physical interface, assign it IP address and everything will work as if nothing has happened. My physical interface and the new VLAN interface both with IP Addresses will work seamessly, Am i right?