Enabling vlans breaks dns

Installing and Using OpenWrt
1

so i'm in my openwrt web config
I go to network > switch and change CPU (eth0) from untagged to tagged
i get the banner saying network lan was changed from eth0 to eth0.1
I click save and apply

my internet stops working both wired and wireless
I undo these steps and it is working again

(by stops wortking I mean everything says could not resolve address including the network diagnostics page on the openwrt web config)

any ideas whats causing this?

I am trying to add vlans for multiple wifi ssid's for roommates

2

You do not need VLANs to have several SSIDs, have a look to the "guest network" guide instead.

3

I need vlans to connect to my managed switch in my server rack in the next room to isolate my iot devices and my servers and my lan devices

4

ignore this topic I stated what I wanted wrong im making a new topic. moderators please delete