Why are Network Control Protocols used in PPP? | |
| to establish and terminate data links | |
| to provide authentication capabilities to PPP | |
| to manage network congestion and to allow quality testing of the link | |
| to allow multiple Layer 3 protocols to operate over the same physical link | |
| What is the data transmission rate for the DS0 standard? | |
| 44 kb/s | |
| 64 kb/s | |
| 1.544 Mb/s | |
| 44.736 Mb/s | |
| In which two layers of the OSI model are key differences found between a LAN and a WAN. (Choose two.) | |
| Layer 1 | |
| Layer 2 | |
| Layer 3 | |
| Layer 4 | |
| Layer 6 | |
| Layer 7 | |
| Which statement is true about the Cisco implementation of the HDLC protocol? | |
| It supports authentication. | |
| It has a universally compatible frame format. | |
| It is the default encapsulation for serial interfaces on Cisco routers. | |
| It does not support multiple protocols across a single link. | |
 Refer to the exhibit. A network administrator has a connectivity problem between the serial interfaces of Merida and Vargas. What is the cause of the problem? | |
| Authentication is required on the serial link. | |
| The encapsulation is misconfigured. | |
| The IP addresses are on different subnets. | |
| The serial interface on Vargas is shutdown. | |
| The loopback interfaces on both routers are not configured. | |
 Refer to the exhibit. What statement is true about the exhibited output? | |
| LCP is in the process of negotiating a link. | |
| LCP and NCP are waiting for CHAP authentication to complete. | |
| LCP negotiation has completed successfully, but NCP negotiation is in progress. | |
| LCP and NCP negotiation is complete, and the data link service is available to carry packets. | |
| Which three statements are true regarding LCP? (Choose three.) | |
| It is responsible for negotiating link establishment. | |
| It negotiates options for Layer 3 protocols running over PPP. | |
| It uses MD5 encryption while negotiating link-establishment parameters. | |
| It terminates the link upon user request or the expiration of an inactivity timer. | |
| It can test the link to determine if link quality is sufficient to bring up the link. | |
| It monitors the link for congestion and dynamically adjusts the acceptable window size. | |
| Why are Frame Relay paths referred to as virtual? | |
| Frame Relay PVCs are created and discarded on demand. | |
| The connections between PVC endpoints act like dialup circuits. | |
| There are no dedicated circuits to and from the Frame Relay carrier. | |
| The physical circuits inside the Frame Relay cloud do not contain exclusive links for a specific Frame Relay connection. | |
| What best describes the use of a data-link connection identifier (DLCI)? | |
| an address identifying a virtual circuit | |
| a logical address identifying the DCE device | |
| an address identifying a Layer 3 service across a Frame Relay network | |
| a logical address identifying the physical interface between a router and a Frame Relay switch | |
| What two services allow the router to dynamically map data link layer addresses to network layer addresses in a Frame Relay network? (Choose two.) | |
| ARP | |
| ICMP | |
| Proxy ARP | |
| Inverse ARP | |
| LMI status messages | |
| Which three statements describe functions of the Point-to-Point Protocol with regards to the OSI model? (Choose three.) | |
| operates at all layers of the OSI model | |
| provides a mechanism to multiplex several network layer protocols | |
| can be configured on both synchronous and asynchronous serial interfaces | |
| uses Layer 3 of the OSI model to establish and maintain a session between devices | |
| uses the data link layer to configure such options as error detection and compression | |
| uses network control protocols to test and maintain connectivity between devices | |
| At what physical location does the responsibility for a WAN connection change from the user to the service provider? | |
| demilitarized zone (DMZ) | |
| demarcation point | |
| local loop | |
| cloud | |
| What does a Frame Relay switch use to inform the sender that there is congestion? | |
| FECN | |
| BECN | |
| DE | |
| FCS | |
 Refer to the exhibit. What statement is true about the debug output? | |
| R2 is using PAP instead of CHAP. | |
| The routers have different CHAP passwords configured. | |
| The administrator performed a shutdown on the R2 PPP interface during negotiation. | |
| The Layer 3 protocol negotiation caused the connection failure. | |
| Which two statements describe the function of time-division multiplexing? (Choose two.) | |
| Multiple data streams share one common channel. | |
| Conversations that require extra bandwidth receive any unused time slices. | |
| Time slots are utilized on a first-come, first-served basis. | |
| Time slots go unused if a sender has nothing to transmit. | |
| Priority can be dedicated to one data source. | |
| When customers use credit cards to make purchases at a small business, a modem is heard dialing a telephone number to transfer the transaction data to the central office. What type of WAN serial connection is in use? | |
| leased line | |
| point-to-point | |
| circuit switched | |
| packet switched | |
| Which best describes data communications equipment (DCE)? | |
| serves as data source and/or destination | |
| responsible for negotiating windowing and acknowledgements | |
| physical devices such as protocol translators and multiplexers | |
| equipment that forwards data and is responsible for the clocking signal | |
| Permanent virtual circuits and switched virtual circuits are both part of which option for WAN connectivity? | |
| leased line | |
| cell switching | |
| packet switching | |
| circuit switching | |
| Which field of a frame uses error detection mechanisms to verify that the frame is not damaged in transit? | |
| FCS | |
| MTU | |
| flag | |
| control | |
| protocol | |
| What occurs in the encapsulation process as a data packet moves from a LAN across a WAN? | |
| The Layer 2 encapsulation changes to a format that is appropriate for the WAN technology. | |
| The Layer 3 encapsulation changes to a format that is appropriate for the WAN technology. | |
| Both Layer 2 and Layer 3 encapsulation change to a technology that is appropriate for the WAN. | |
| Both Layer 2 and Layer 3 encapsulation remain constant as the data packet travels throughout the network. | |
 Refer to the exhibit. The network administrator is configuring R1 to connect to R2, which is a non-Cisco router. Which encapsulation method will need to be configured for communication to occur? | |
| HDLC | |
| HSSI | |
| ISDN | |
| IPCP | |
| PPP | |
| A company is implementing dialup services for remote workers to connect to the local network. The company uses multiple Layer 3 protocols and requires authentication for security. Which protocol should be used for this remote access? | |
| LMI | |
| PPP | |
| HDLC | |
| Frame Relay | |
| Which two options can LCP negotiate? (Choose two.) | |
| compression | |
| authentication | |
| dynamic flow control | |
| network layer address for IP | |
| connection-oriented or connectionless communication methods | |
| What statement best describes cell switching? | |
| It uses a dedicated path between endpoints. | |
| It creates a permanent physical link between two points. | |
| It uses DLCIs to identify virtual circuits. | |
| It creates fixed-length packets that traverse virtual circuits. | |
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