patm device on FreeBSD 9.2

[Nomad Esst]

I've recently configured my kernel with the following optionsdevice        patmdevice        utopiadevice        atmoptions       NATMoptions       LIBMBPOOLIn order to use patm device on my FreeBSD 9.2 AMD64.Here are the configurations for a back to back connection
ifconfig patm0 10.10.10.1 255.0.0.0atmconfig natam add 10.10.10.2 0 100 aal5
after setting these configurations, I can not even ping the other side! Another problem is that using tcpdum on patm0 interface causes the following error:
tcpdump:    patm0: No such device(BIOCSETIF failed: Device not configured)
Please help me using this device on my system.Thanks in advance ...