You can run 1 masternode per port on same IP.

Huh - I couldn't get that working - got an error like "port must be 11990 for mainnet" or something
edit: actually, looking thru the masternode list - It looks like all of them are on the default port
Broke, it means that your port of router is open! Why don't you try a VPS on Vultr or Digitalocean? It's much easir. I'll code a script that help setup masternode. It'd be release soon.