2.5 In an Ethemet network, which of the following is true: a. Ethemet switches (a.k.a bridges) lean addresses by looking at the destination address of packets as they pass by. b. Ethemet hubs and repeaters leam addresses by looking at the addresses of packets as they pass by. c. A correctly operating Ethemet switch never sends a packet to the wrong outgoing port. d. Ethemet switches (a.k.a bridges) learm addresses by looking at the source address of packets as they pass by. e. Collisions occur less on a switched Ethemet network because links run faster 2.6 This statement is false a. Headers are added as packets travel down the protocol stack b. Headers are removed as packets travel down the protocol stack c. Headers are removed as packets travel up the protocol stack d. Trailers may be added as the packet travels down the protocol stack 2.3 "Layering" is commonly used in computer networks because: a. It forces all network software to be written in ANSI 'C'. b. Encapsulation is the lowest overhead method to transmit data. c. It allows widespread code and implementation re-use. d. It keeps networks warm enabling them to run faster. 2.4 The Intemet Protocol (IP) provides: a. a connection-oriented service. b. reliable delivery. c. best-effort delivery. d. in-sequence delivery.