@Armodon ,
@SchmuFoo is right, you can define which IP address the Monocle Gateway uses by overriding the setting via the monocle.properties file. By default Monocle Gateway just auto chooses the first interface it finds.
You would change #rtsp.host=0.0.0.0 to rtsp.host=YOUR_IP_ADDRESS
#--------------------------------------
# RTSP SERVICE PROPERTIES
#--------------------------------------
#rtsp.host=0.0.0.0
#rtsp.port=8555
#rtsp.ssl.port=443
You can technically override the port as well if you were fronting/proxying with some TCP proxy server (… Stunnel, HA Proxy). But in the end the Alexa devices will only connect on port 443.
Thanks, Robert