simple command line tool to scan a range of ports internally, to verify http connectivity. this is not intended to scan ports on remote servers
useage:
# check ports 8080 to 18080.
node port-scan.js yourdomain.com 8080 18080
#output
# ...
#closed: 8077
#closed: 8078
#closed: 8079
#open port: 8080
#closed: 8081
#closed: 8082
#closed: 8083
#closed: 8084
#...
this seems to be at least useful for local firewall issues, although internal routing may get passed a network firewall that would otherwise block requests...