trying to access the fortigate internally

[chanklish]

hello

I am trying to connect to the fortigate internally but everytime i connect it to my network , my connection is out 

i want to be able to access it from 192.168.20.0/24
i tried putting ip from this subnet on the mgmt or lan2 and connect it to the core switch i have , but the internet is gone from computers connected to this subnet ( but i am able to receive an ip from my dhcp router so connection between fortigate->switch-> router is working 

removing the cable from the switch , internet work .. i believe maybe i have a loop 

Static routes from the fortigate (10.77.77.2 is my main router - same as dhcp ) - it has a route 0.0 .0. 0 / 0 to 10.77.77.1 ( lan switch in fortigate )

[AEK]

Hello

Can you share a diagram?

[chanklish]

192.168.20.0/24 on my router. And  router routes to 10.77.77.1 (FortiGate). And  FortiGate routes to 192.168.85.1 (WAN).

[gfleming]

You should not be putting 192.168.20.0/24 onto the FortiGate, anywhere. It sounds like this exists on your router so keep it there. Also never use mgmt interface for anything except mgmt traffic.

So you have 192.168.20.0/24 on your router. And your router routes to 10.77.77.1 (your FortiGate). And your FortiGate routes to 192.168.85.1 (WAN).

Do you have firewall policies to allow traffic from lan to wan1?

[chanklish]

yes this is mostly my network

i have a rule for internet for 192.168.20.0/24 (i have internet on my 20.x computer)

i want to be able to manage the fortigate from my pc 20.x

[gfleming]

Are you allowing HTTPS and SSH on the lan interface?

[chanklish]

i am not sure , but the problem is that internet goes offline on the computer when i connect the fortigate lan to the router 

[gfleming]

OK what is your router's default route pointing to before you connect the fortigate to it? You probably need to reconfigure your router...

[chanklish]

all routes goes to the fortigate on lan 1

maybe i can nat the 10.77.77.1 (my FortiGate) to access it from the pc

[gfleming]

I'm asking you what is the router configured for before you connect it to the FortiGate LAN?

Presumably you have internet access through this router that is working until you connect the FortiGate LAN interface?

We need to understand how the router is configured.

And no you don't need NAT.... you need to focus on your network and routing configuraiton..