The routers RTA and RTB are located in the same autonomous system. The BGP related configuration is as follows, then RTA and RTB are _____.
RTA]
bgp 100
timer keepalive 10 hold 30
peerRTB as-number 100
[RTB]
bgp 100
timer keepalive 30 hold 90
peerRTA as-number 100

IS-IS routers transfer link status to each other. The information describing the link status is encapsulated in _______.

OSPF TotallNSSA area will definitely not inject ______ type LSA.

In the topology shown in the figure, the following configurations are performed on RTA, RTB, RTC and RTD respectively:
RTA-LoopBack0] ip address 1.1.1.1 255.255.255.255
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
RTA-ospf-1]import-route direct
RTB-LoopBack0] ip address 2.2.2.2 255.255.255.255
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
RTB-ospf-1]import-route direct
RTC-LoopBack0] ip address 3.3.3.3 255.255.255.255
RTC]ospf 1
RTC-ospf-1]area 0
RTC-ospf-1-area-0.0.0.0]network 20.0.0.0 0.0.0.255
RTC-ospf-1-area-0.0.0.0]area 2
RTC-ospf-1-area-0.0.0.2]nssa
RTC-ospf-1-area-0.0.0.2]network 30.0.0.0 0.0.0.255
RTC-ospf-1-area-0.0.0.2]network 3.3.3.3 0.0.0.0
RTD-LoopBack0] ip address 4.4.4.4 255.255.255.255
RTD]ospf 1
RTD-ospf-1]area 2
RTD-ospf-1-area-0.0.0.2]network 30.0.0.0 0.0.0.255
RTD-ospf-1-area-0.0.0.2]nssa
RTD-ospf-1]import-route direct
Which of the following routes may not exist in the RTD routing table ______.

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 1.1.1.1 0.0.0.0
RTA-ospf-1-area-0.0.0.1]network 10.0.0.0 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 192.168.4.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.7.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.8.0 0.0.0.255
RTA-ospf-1-area-0.0.0.1]network 192.168.15.0 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-0.0.0.1]abr-summar192.168.0.0 255.255.252.0
Then which of the following routes may exist in the RTC routing table_____