iPhone remote connection to ion with one network port

Hi all my High school has an Ion and I’m trying to figure out how to connect the console to a dedicated lighting router. The console only has one network port and is being used for connection to the ETCNet port below the console. I can’t seem to figure out if I connect the console to the router then send a cable down to the ETCNet port using the modem port on the router? Any help would be appreciated!

P.S. How much does the upgrade to win 7 typically cost? Our console crashes sometimes during a show causing missed/late cues. It was probably manufactured somewhere in the 2010 range as it still has the flat keys with beveled edges.