A.802.1Q native VLAN frames are untagged by default.
B.802.1Q trunking ports can also be secure ports.
C.802.1Q trunks can use 10 Mb/s Ethernet interfaces.
D.802.1Q trunks require full-duplex， point-to-point connectivity.
E.802.1Q trunks should have native VLANs that are the same at both ends.