PPP protocol work in the OSI seven layer model

When a router is powered on, the router reads the configuration file saved in the default save directory to get itself initialized. If the configuration file does not exist in the default save directory, what does the router use to initialize itself?

In the router, type the command displays RIP routing information, see the show results are: peer 192.168.1.2 on Serial0/0/1, which is the router 192.168.1.2 ().

Which of the following fields are contained in an ARP packet?

UDP is connectionless and must use which to provide the reliability of the transmission?