Your Philips hue bridge gets assigned an ip address by the router that it is connected to via the ethernet cable. If the bridge is connected properly and making a connection, the 2nd or middle light on the bridge will be solid. If the 2nd light on your bridge is not on at all, make sure your bridge is plugged in to the back of your router. If it is connected and the light is still not on, try another port on the router and try another known working ethernet cable. If the light does not come on at all, it is possible that the bridge is defective and you should either call Philips technical support or exchange the bridge at the point of sale.
Disable Any VPN Service
Make sure your device is not connected to a VPN (Virtual Private Network). An example of a VPN would be services like NordVPN, Private Internet Access, ExpressVPN, and Proton VPN. A VPN puts your device on a different network and it will not be able to find your hue bridge.
There are a few different ways that you can find the ip address assigned to your Philips Hue Bridge, the easiest is through the Meethue Discovery link below.
If your bridge is on your network, the link should bring up a page that will look like the image below. It will display the MAC address, the IP Adrdress, and the Port number.
If you are using a device not on the same network as your bridge or your bridge has not been assigned an ip address by your router, it will not show any information like in the screenshot below.
Disable DHCP in Hue App
This method is only possible if you can connect to your bridge. To do this, open the Philips Hue Application and go into Settings > Bridge Settings > Network Settings. Once in Network settings, disable DHCP and it will display the IP address that is currently assigned to your Hue Bridge.
Install Fing Application
Another way is with this network application called Fing. It is a free application that will show you all devices and ip address assigned to them on your network.
How to Set a Static Ip Address to your Hue Bridge
In some cases of bridge connectivity it can help to assign a static ip address to your Philips hue bridge. It is recommended to leave it on DHCP, meaning it will automatically be assigned an ip address from the router. If you do not understand how these settings work, you may want to contact your router manufacturer.
Go to Settings > Bridge Settings.
Select Network Settings.
Toggle off DHCP.
You will then be able to see and modify your Hue Bridge IP Address. If you do change it, remember to select Save at the top once finished.