Switch's access port was configured to use voice vlan "20" for IP Voice traffic from IP phone and vlan "10" for data traffic from device attached to the IP phone. All of switches was configured to send MAC notification traps.
IP phone's MAC address received with mac notification trap is in data vlan 10.
SNMPv2-SMI::enterprises.220.127.116.11.18.104.22.168.51 = Hex-STRING: 01 00 0A 00 14 A9 XX 6E F1 00 03 00
0x0A = 10 Vlan
Really phone is in Voice vlan 20.
sw1#sh ip dhcp snooping binding | inc 6E:F1|VLAN
MacAddress IpAddress Lease(sec) Type VLAN Interface
00:14:A9:XX:6E:F1 10.xxx.xxx.xxx 42570 dhcp-snooping 20 FastEthernet0/1
Does anybody have any thoughts?