In the topology shown in the figure, the following configurations are performed on RTA and RTB respectively:
RTA]ospf 1
RTA-ospf-1]area 1
RTA-ospf-1-area-0.0.0.1]network 10.0.0.0 0.0.0.255
RTB]ospf 1
RTB-ospf-1]area 1
RTB-ospf-1-area-0.0.0.1]network 10.0.0.0 0.0.0.255
RTB-ospf-1-area-0.0.0.1]area 0
RTB-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255
If you need to configure area 2 as an NSSA area and require all interface addresses of RTA to be pingable on RTD, how should you configure it on RTC and RTD?

About the difference between system policy routing and interface policy routing. The correct statement is _________

In the topology shown in the figure, the following configurations are performed on RTA and RTB respectively:
RTA-ospf-1-area-0.0.0.1]network 192.168.0.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.1.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.2.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.3.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.4.0 0.0.0.255 It is now required that the RTC must not learn the routes configured in the above RTA. What configurations can be performed on the router?

As shown in the figure, 4 routers are connected to an Ethernet link. The router interface is a broadcast network type, and the DIS election is carried out and an adjacency relationship is established. If the RTA restarts at this time, after the restart is completed, the DIS on this link is ______.

If the BGP neighbor is successfully established, the neighbor status viewed by the displabgp peer command is ______.