Wendell Odom - CCENT/CCNA ICND1 640-822 Official Cert Guide

D and F

A and G

B. Adjacent-layer interaction occurs on one computer, with two adjacent layers in the model. The higher layer requests services from the next lower layer, and the lower layer provides the services to the next higher layer.

B. Same-layer interaction occurs on multiple computers. The functions defined by that layer typically need to be accomplished by multiple computersfor example, the sender setting a sequence number for a segment, and the receiver acknowledging receipt of that segment. A single layer defines that process, but the implementation of that layer on multiple devices is required to accomplish the function.

A. Encapsulation is defined as the process of adding a header in front of data supplied by a higher layer (and possibly adding a trailer as well).

D

C

A

F

C and E. OSI includes the transport layer (not transmission layer) and the network layer (not Internet layer).

D

A

B

B, D, and E. Routers, wireless access point Ethernet ports, and PC NICs all send using pins 1 and 2, whereas hubs and switches send using pins 3 and 6. Straight-through cables are used when connecting devices that use the opposite pairs of pins to transmit data.

B

A

A and C

C and D

A

B, C, and E

C

B

B. The 4-wire circuit cable supplied by the Telco connects to the device acting as the CSU/DSU. That can be an external CSU/DSU, or a CSU/DSU integrated into a router serial interface card. LAN switches do not have serial interfaces, and router serial interfaces do not have transceivers.

B

A

E

E. Although HDLC has an Address field, its value is immaterial on a point-to-point link, as there is only one intended recipient: the device on the other end of the circuit.

A

B. One of the main advantages of Frame Relay is that a router can use a single access link to support multiple VCs, with each VC allowing the router to send data to a different remote router. To identify each VC, the router must use a different DLCI, because the DLCI identifies the VC.

A and C. The network layer defines logical addressing, in contrast to physical addressing. The logical address structure allows for easy grouping of addresses, which makes routing more efficient. Path selection refers to the process of choosing the best routes to use in the network. Physical addressing and arbitration typically are data link layer functions, and error recovery typically is a transport layer function.

C and E

A

B. 224.1.1.1 is a class D address. 223.223.223.255 is the network broadcast address for class C network 223.223.223.0, so it cannot be assigned to a host.

D

D and F. Without any subnetting in use, all addresses in the same network as 10.1.1.1all addresses in Class A network 10.0.0.0must be on the same LAN. Addresses separated from that network by some router cannot be in network 10.0.0.0. So, the two correct answers are the only two answers that list a valid unicast IP address that is not in network 10.0.0.0.

D

F

C

B and C

A and C

C

D

D. PC1 interprets the absence of an acknowledgment to mean that PC1 cannot tell if PC2 got any of the segments. As a result, PC1 resends all segments.

D

D and E

D and E

C. TCP, not UDP, performs windowing, error recovery, and ordered data transfer. Neither performs routing or encryption.

C and F. The terms packet and L3PDU refer to the data encapsulated by Layer 3. Frame and L2PDU refer to the data encapsulated by Layer 2.

B. Note that the hostname is all the text between the // and the /. The text before the // identifies the application layer protocol, and the text after the / represents the name of the web page.

A and D. VoIP flows need better delay, jitter, and loss, with better meaning less delay, jitter, and loss, as compared with all data applications. VoIP typically requires less bandwidth than data applications.

C. Intrusion Detection Systems (IDS) monitor packets, comparing the contents of single packets, or multiple packets, to known combinations (signatures) that typically imply that a network attack is occurring.

A. A virtual private network (VPN) is a security feature in which two endpoints encrypt data before forwarding it through a public network such as the Internet, providing privacy of the data inside the packets.

A. A switch compares the destination address to the MAC address table. If a matching entry is found, the switch knows out which interface to forward the frame. If no matching entry is found, the switch floods the frame.

C. A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table).

A. A switch floods broadcast frames, multicast frames (if no multicast optimizations are enabled), and unknown unicast destination frames (frames whose destination MAC address is not in the MAC address table).

B. Switches learn MAC table entries by noting the source MAC address of each received frame and the interface in which the frame was received, adding an entry that contains both pieces of information (MAC address and interface).

A and B. When the frame sent by PC3 arrives at the switch, the switch has learned a MAC address table entry for only 1111.1111.1111, PC1s MAC address. PC3s frame, addressed to 2222.2222.2222, is flooded, which means it is forwarded out all interfaces except for the interface on which the frame arrived.

A. A collision domain contains all devices whose frames could collide with frames sent by all the other devices in the domain. Bridges, switches, and routers separate or segment a LAN into multiple collision domains, whereas hubs and repeaters do not.

A, B, and C. A broadcast domain contains all devices whose sent broadcast frames should be delivered to all the other devices in the domain. Hubs, repeaters, bridges, and switches do not separate or segment a LAN into multiple broadcast domains, whereas routers do.

B and D

A and B

B

B

A

F

D

B and C

B. If both commands are configured, IOS accepts only the password as configured in the enable secret command.

B and C

B. The first nonblank character after the banner login phrase is interpreted as the beginning delimiter character. In this case, its the letter t. So, the second letter tthe first letter in theis interpreted as the ending delimiter. The resulting login banner is the text between these two tsnamely, his is.

A. The setting for the maximum number of MAC addresses has a default of 1, so the switchport port-security maximum command does not have to be configured.

A, D, and F. To allow access via Telnet, the switch must have password security enabled, at a minimum using the password vty line configuration subcommand. Additionally, the switch needs an IP address (configured under the VLAN 1 interface) and a default gateway when the switch needs to communicate with hosts in a different subnet.