nmap -sS 192.168.1.1 -p 8989

Starting Nmap 4.20 ( http://insecure.org ) at 2008-02-02 23:10 EET
Interesting ports on 192.168.1.1:
PORT     STATE  SERVICE
8989/tcp closed unknown
MAC Address: 00:02:CF:54:6B:7D (ZyGate Communications)

Nmap finished: 1 IP address (1 host up) scanned in 0.234 seconds