The network administrator of a certain enterprise needs to set a subnet mask to divide the class C network 211.110.10.0 that he is responsible for into at least 8 subnets. How many subnet masks can be used for division? (multiple choice)

The well-known port number of the transport layer protocol used by DNS is ______.

The two branches of XYZ company are located in different regions, and a wide area network connection must be established between them. According to the plan, the WAN adopts the PPP protocol. Considering network security, it is required that password-type message information is not allowed to be transmitted in clear text on the network. Then which PPP authentication protocol should be adopted?

Two empty-configured MSR routers RTA and RTB are interconnected back-to-back through their Serial1/0 interfaces. Do the following configuration on the two routers:
RTA: skip
[RouterA-Serial1/0] link-protocol fr ietf
[RouterA-Serial1/0] ip address 10.1.1.1 30
[RouterA-Seria11/0] fr map ip 10.1.1.2 30
RTB: [RouterB-Serial1/0] link-protocol fr ietf
[RouterB-Serial1/0] interface serial0/0.1
[RouterB-Serial1/0.1] ip address 10.1.1.2 30
[RouterB-Serial1/0.1] fr map ip 10.1.1.1 30
The physical link between the routers is good, so the correct statement below is ______. (Multiple choice)

An empty-configured MSR router is connected to the same OSPF network through multiple interfaces, and OSPF is enabled on all these interfaces. After the configuration is completed, the router has successfully learned the OSPF routes in the network.
Now run the following command on an OSPF interface of the router:
[MSR-GigabitEthernet0/0]ospf cost 256
In the case of keeping other configurations unchanged, the correct understanding of the configuration is _____.