According to this picture, what can we judge? (Multiple choice)

When troubleshooting the EBGP neighbor relationship, you find that the two directly connected devices use the loopback interface to establish a connection, so execute display current-configuration configuration bgp to check the unitary setting of peer ebgp-max-hop hop-count, which of the following statements is correct?

Compared with the OSPFv2 message header, what fields are added in the OSPFv3 message header?

As shown in the figure, a sham link is established between PE1 and PE2 through the LoopBackD interface. CE2 can learn the route to the 192.168.1.0/24 network segment (the direct route on CE1) through the sham link and backdoor link. If you keep the default configuration, the cost value of the route from CE2 to the 192.168.1.0/24 network segment should be (). (Please fill in the Arabic numerals directly, without symbols)

What are the work that needs to be performed in the closing phase after the cutover acceptance is completed? (Multiple choice)