Among the following routing protocols, the one that belongs to the IGP is ______, and the one that uses the path vector algorithm is ______.

In the IS-IS network as shown in the figure, the verification part of each router is configured as follows
RTA-Serial2/0]isis authentication-mode md5 h3c
RTB-isis-1]area-authentication-mode md5 h3c
RTC-isis-1]domain-authentication-mode md5 h3c
Then RTA and RTB______ establish a neighbor relationship, and RTB and RTC______ establish a neighbor relationship.

A BGP connection is established between the routers RTA and RTB and they have learned routes from each other. Both RTA and RTB use default timers.
If the link between routers is congested and RTA cannot receive the Keepalive message from RTB, which of the following consequences will occur?

Which of the following BGP attributes are recognized mandatory attributes?

Execute the following commands on the MSR router RTA:
RTA-GigabitEthernet0/0]ip address 192.168.1.1 24
RTA-GigabitEthernet0/0]uit
RTA]router id 2.2.2.2
RTA]ospf 1 router-id 1.1.1.1
RTA-ospf-1]uit
RTA]interface LoopBack 0
RTA-LoopBack0]ip address 3.3.3.3 32
From the above configuration, it can be judged that the Router ID of RTA's OSPF process 1 is ______