Indicates the type of the frame that can be received by a VLAN interface.
Options:
1. ethernetii(1) -For the frame format of ethernetii(1), see RFC894.
2. ethernetsnap(2) -The value is not supported.
3. ethernet8022(3) -The value is not supported.
4. ethernet8023(4) -The value is not supported.
Currently, only ethernetii(1) is supported.