GUI Access unavailable on fortigate 30e

[Tonero]

Hi all. I'm stuck with a problem. I've been using fortigate 30e for a couple of years now. Connected to it is a mail server, a laptop on a DMZ and access to a local network. We changed ISP last week and some issues started cropping up with connectivity to the network. We've reverted to the ISP we were using before but there was an issue with LAN forwarding to the mail server. Yesterday I backed up the configuration on the GUI and changed from manual settings to DHCP to see if the error could be solved. A message appeared saying that it would mean changing the DHCP server. I agreed and since then, it has been impossible to log on to the GUI, even on a laptop and utilizing the default 192.168.1.99 Any ideas on what to do? I'm not versed in IT, unfortunately just the basics... Thanks in advance

[Toshi_Esumi]

FG30E doesn't have DMZ port so you must have split the lan hard-switch to have the DMZ interface. Since you seem to have broken DHCP server config, you need to use a static IP within the subnet on the laptop, then try all ports one by one. But getting into it via console with CLI would be much easier if you're willing to learn CLI.

[Tonero]

Thanks Toshi. I'm willing to learn CLI. Any suggestion on how to start or any resources that can help? Are there specific commands that I need for restoring the DHCP server configuration?

[Toshi_Esumi]

First, you need to find out how those lan ports are split to make the "DMZ". Is that lan4 port or other port?

It's under "config sys virtual-switch". "show" would show all ports in hard switch "lan". If it's separated you wouldn't see the port.

Then check what IP is configured on the port under "config sys int". Again "show" would show all config on all ports.

And then finally, find the IP configured as a gateway under "config sys dhcp server". Those are grouped with "edit 1", "edit 2", and so on. You probably broke the section serving the port subnet.

You should just search on the internet like "fortigate cli dhcp server configuration" then you can find a bunch of articles mostly inside of Fortinet's document library, which you can learn how DHCP server should be configured.

[Tonero]

Thanks so much. Will do so.

[Tonero]

Thanks so much. Will do so.

[Tonero]

I was able to log in with the laptop using the static IP you suggested. Then I restored the configuration from the backup I made before effecting the changes some days ago. Now I can log into the GUI as before. Thanks so much!