The output information of a router is as follows. Which of the following reasons cause the OSPF adjacency relationship to fail to be established normally? (Multiple choice)

Regarding BGP/MPLS IPVPN data forwarding, which of the following descriptions is wrong?

In the VLAN aggregation technology, multiple Sub-VLANs are used to isolate the wide recruitment area, and these Sub-VLANs are aggregated into a logical Super-VLAN. A company divides different departments into different Sub-VLANs because of the Sub-VLAN. VLAN not only includes physical connections, but also can establish a three-layer VLANIF interface, which can directly communicate with the external network on the three-layer.

CutoverThe previous information collection can be used to determine whether the services before and after the cutover are normal.

Configured on an interface: isis timer hello 5 level-2, which of the following statements is correct?