USG Flex 100 H as a router questions

Pinknots

Guys, running into an issue when trying to setup my USG flex 100H. Bear with me as I lack lots of networking knowledge.

my current config goes Modem→Router/WAP(asus consumer grade router)→LAN Devices

so I’m trying to configure my network to go Modem→USGFlex→Router(configured as a WAP and no longer a router)→Lan devices

When I connect the USG flex directly to the modem it has zero clue it’s supposed to be handling the routing now. How do I configure this? Do I need to set the default gateway to the old default gateway of my router?
I plan on having the firewall ahead of my WAP and have the firewall handle the routing to connect an internet facing server ahead of my lan/off the hardware firewall. But when connected off the modem I get no connection.

With old configuration of WAN feed in right off my router it worked fine but isn’t secure that way for internet facing server as traffic would traverse my lan to get to the server.

Xydocq

hi @Pinknots

What settings did you use on the Asus Router to connect to the Internet? You might have to copy the settings from there to your USG.

I am using a cable-connection, and all I had to do, was to set my USG to get public IP on DHCP-mode on wan-port. I was using an Asus ZenWifi AX before.

PeterUK

So you likely have LAN working to get to FLEX UI but your ISP is not allow a MAC change for you to get a WAN IP with most ISP you need to power off the modem for a bit or copy the WAN MAC from your old router to FLEX.

Xydocq

hi @Pinknots

What settings did you use on the Asus Router to connect to the Internet? You might have to copy the settings from there to your USG.

I am using a cable-connection, and all I had to do, was to set my USG to get public IP on DHCP-mode on wan-port. I was using an Asus ZenWifi AX before.