6. Suppose Host A sends Host B a TCP segment encapsulated in an IP datagram. When Host B receives the datagram, how does the network layer in Host B know it should pass the segment (that is, the payload of the datagram) to TCP rather than to UDP or to something else?
7. In section 4.2, FIFO, Priority, Round Robin (RR), and Weighted Fair Queuing (WFQ) packet scheduling disciplines are discussed. What is the difference between these scheduling disciplines? Which of these queuing disciplines ensures that all packets depart in the order in which they arrived?
Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 223.1.17.0/24. Also, suppose that Subnet 1 is required to support at least 60 interfaces, Subnet 2 is required to support at least 90 interfaces, and Subnet 3 is required to support at least 12 interfaces. Provide three network addresses (of the form a.b.c.d/x) that satisfy these constraints.