With Recalbox, it is possible to define the IP address to use with the Wi-Fi connection, this is can be done with the recalbox.conf file.
Recalbox allows managing network parameters for specific use cases, a mistake in this part could drive to conflict or other issues, the best practice is using your router to do this tuning. Use this tutorial with intent.
Open the recalbox.conf file and find these lines:
## Wifi - static IP
## if you want a static IP address, you must set all 4 values (ip, netmask, gateway and nameservers)
## if any value is missing or all lines are commented out, it will fall back to the
## default of DHCP. For nameservers, you must set at least 1 nameserver.
;wifi.ip=manual ip address (ex: 192.168.1.2)
;wifi.netmask=network mask (ex: 255.255.255.0)
;wifi.gateway=ip address of gateway (ex: 192.168.1.1)
;wifi.nameservers=ip address of domain name servers, space separated (ex: 192.168.1.1 8.8.8.8)
Remove the symbol ; beginning of last three lines and update values as desired. Here is an example:
wifi.ip=192.168.1.10
wifi.netmask=255.255.255.0
wifi.gateway=192.168.1.254
wifi.nameservers=8.8.8.8 8.8.4.4
Restart your Recalbox to acknowledge new parameters using the command reboot.