Unable to discover ILOM

I'm having an error in discovering ILOMs for Ops Center. The ILOM can be pinged but it doesn't return a service tag for the server. Port 6481 is enabled on the firewall for both TCP and UDP so that possibility is ruled out.

Here is the error message in the proxy controllers logs.

Feb 24, 2014 2:26:51 AM com.sun.hss.domain.internal.UDPProbe$1 run

INFO: thr#1603:"UDP Listener" Cannot obtain service tag / agent data.

java.net.SocketException: Socket closed

     at java.net.PlainDatagramSocketImpl.receive0(Native Method)

     at java.net.PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:188)

     at java.net.DatagramSocket.receive(DatagramSocket.java:725)

     at com.sun.hss.domain.internal.UDPProbe$1.run(UDPProbe.java:143)