First of all make sure your Recalbox is connected to the network with an ethernet cable or USB wifi adaptor.
You think Recalbox is connected on the network but you are not sure, let's see how checking this easily!
Press Start, choose UPDATES and LAUNCH UPDATES:
An update is available: Recalbox is well connected to the network.Please connect a network cable: Recalbox is not connected to your network and there is an issue (network misconfiguration, defective cable, etc.).Usually IP address are not fixed and change at regular time or after every reboot.
You can define a static IP address for easy access to your Recalbox.
You should do this configuration on your router but you can set network parameters of your Recalbox also.
Press START and go to NETWORK SETTINGS. The current IP address is displayed here like 192.168.0.XX.
cmd and press Enter.ping recalbox and press Enter again.192.168.0.XX:> Sending a ping request to RECALBOX with 32 bytes of data:
> Response from 192.168.0.XX : bytes=32 time=1 ms TTL=128
> Answer from 192.168.0.XX : bytes=32 time=1 ms TTL=128
> Response from 192.168.0.XX : bytes=32 time=1 ms TTL=128
> Ping statistics for [...]
Applications/Utilities/Terminal.arp -a and press Enter.