CISCO CCNA Exam – Q333

Which two statistics appear in “show frame-relay map” output? (Choose two.)

A. the number of BECN packets that are received by the router
B. the value of the local DLCI
C. the number of FECN packets that are received by the router
D. the status of the PVC that is configured on the router
E. the IP address of the local router

Correct Answers: B,D

Explanation:
Sample “show frame-relay map” output:
R1#sh frame map
Serial0/0 (up): ip 10.4.4.1 dlci 401(0x191,0x6410), dynamic,
broadcast,, status defined, active
Serial0/0 (up): ip 10.4.4.3 dlci 403(0x193,0x6430), dynamic,
broadcast,, status defined, active
Serial0/0 (up): ip 10.4.4.4 dlci 401(0x191,0x6410), static,
CISCO, status defined, active

CISCO CCNA Exam – Q332

Users have been complaining that their Frame Relay connection to the corporate site is very slow. The network administrator suspects that the link is overloaded.
CISCO CCNA Exam – Q332

Based on the partial output of the Router# show frame relay pvc command shown in the graphic, which output value indicates to the local router that traffic sent to the corporate site is experiencing congestion?

A. DLCI = 100
B. last time PVC status changed 00:25:40
C. in BECN packets 192
D. in FECN packets 147
E. in DE packets 0

Correct Answer: C

Explanation:
If device A is sending data to device B across a Frame Relay infrastructure and one of the intermediate Frame Relay switches encounters congestion, congestion being full buffers, over-subscribed port, overloaded resources, etc, it will set the BECN bit on packets being returned to the sending device and the FECN bit on the packets being sent to the receiving device.

CISCO CCNA Exam – Q331

Which command allows you to verify the encapsulation type (CISCO or IETF) for a Frame Relay link?

A. show frame-relay lmi
B. show frame-relay map
C. show frame-relay pvc
D. show interfaces serial

Correct Answer: B

Explanation:
When connecting Cisco devices with non-Cisco devices, you must use IETF4 encapsulation on both devices. Check the encapsulation type on the Cisco device with the show frame-relay map exec command.

CISCO CCNA Exam – Q330

It has become necessary to configure an existing serial interface to accept a second Frame Relay virtual circuit. Which of the following procedures are required to accomplish this task? (Choose three.)

A. Remove the IP address from the physical interface.
B. Encapsulate the physical interface with multipoint PPP.
C. Create the virtual interfaces with the interface command.
D. Configure each subinterface with its own IP address.
E. Disable split horizon to prevent routing loops between the subinterface networks.
F. Configure static Frame Relay map entries for each subinterface network.

Correct Answers: A, C, D

Explanation:
For multiple PVC’s on a single interface, you must use subinterfaces, with each subinterface configured for each PVC. Each subinterface will then have its own IP address, and no IP address will be assigned to the main interface.

CISCO CCNA Exam – Q329

What occurs on a Frame Relay network when the CIR is exceeded?

A. All TCP traffic is marked discard eligible.
B. All UDP traffic is marked discard eligible and a BECN is sent.
C. All TCP traffic is marked discard eligible and a BECN is sent.
D. All traffic exceeding the CIR is marked discard eligible.

Correct Answer: D

Explanation:
Committed information rate (CIR): The minimum guaranteed data transfer rate agreed to by the Frame Relay switch. Frames that are sent in excess of the CIR are marked as discard eligible (DE) which means they can be dropped if the congestion occurs within the Frame Relay network.

Note: In the Frame Relay frame format, there is a bit called Discard eligible (DE) bit that is used to identify frames that are first to be dropped when the CIR is exceeded.

CISCO CCNA Exam – Q328

Which two statements about using the CHAP authentication mechanism in a PPP link are true? (Choose two.)

A. CHAP uses a two-way handshake.
B. CHAP uses a three-way handshake.
C. CHAP authentication periodically occurs after link establishment.
D. CHAP authentication passwords are sent in plaintext.
E. CHAP authentication is performed only upon link establishment.
F. CHAP has no protection from playback attacks.

Correct Answers: B, C

Explanation:
CHAP is an authentication scheme used by Point to Point Protocol (PPP) servers to validate the identity of remote clients. CHAP periodically verifies the identity of the client by using a three-way handshake. This happens at the time of establishing the initial link (LCP), and may happen again at any time afterwards. The verification is based on a shared secret (such as the client user’s password).

CISCO CCNA Exam – Q327

Refer to the exhibit.
CISCO CCNA Exam – Q327

Which statement describes DLCI 17?

A. DLCI 17 describes the ISDN circuit between R2 and R3.
B. DLCI 17 describes a PVC on R2. It cannot be used on R3 or R1.
C. DLCI 17 is the Layer 2 address used by R2 to describe a PVC to R3.
D. DLCI 17 describes the dial-up circuit from R2 and R3 to the service provider.

Correct Answer: C

Explanation:
DLCI-Data Link Connection Identifier Bits: The DLCI serves to identify the virtual connection so that the receiving end knows which information connection a frame belongs to.
Note that this DLCI has only local significance. Frame Relay is strictly a Layer 2 protocol suite.

CISCO CCNA Exam – Q326

What is the result of issuing the frame-relay map ip 192.168.1.2 202 broadcast command?

A. defines the destination IP address that is used in all broadcast packets on DCLI 202
B. defines the source IP address that is used in all broadcast packets on DCLI 202
C. defines the DLCI on which packets from the 192.168.1.2 IP address are received
D. defines the DLCI that is used for all packets that are sent to the 192.168.1.2 IP address

Correct Answer: D

Explanation:
This command identifies the DLCI that should be used for all packets destined to the 192.168.1.2 address. In this case, DLCI 202 should be used.

CISCO CCNA Exam – Q325

Which PPP subprotocol negotiates authentication options?

A. NCP
B. ISDN
C. SLIP
D. LCP
E. DLCI

Correct Answer: D

Explanation:
The PPP Link Control Protocol (LCP) is documented in RFC 1661. LPC negotiates link and PPP parameters to dynamically configure the data link layer of a PPP connection.
Common LCP options include the PPP MRU, the authentication protocol, compression of PPP header fields, callback, and multilink options.

CISCO CCNA Exam – Q324

What are two characteristics of Frame Relay point-to-point subinterfaces? (Choose two.)

A. They create split-horizon issues.
B. They require a unique subnet within a routing domain.
C. They emulate leased lines.
D. They are ideal for full-mesh topologies.
E. They require the use of NBMA options when using OSPF.

Correct Answers: B, C

Explanation:
Subinterfaces are used for point to point frame relay connections, emulating virtual point to point leased lines. Each subinterface requires a unique IP address/subnet.

Remember, you cannot assign multiple interfaces in a router that belong to the same IP subnet.