CCNA Dumps

Switching Question updated

Question 9

A network administrator needs to configure port security on a switch. Which two statements are true? (Choose two)

A. The network administrator can apply port security to dynamic access ports
B. The network administrator can configure static secure or sticky secure mac addresses in the voice vlan.
C. The sticky learning feature allows the addition of dynamically learned addresses to the running configuration.
D. The network administrator can apply port security to EtherChannels.
E. When dynamic mac address learning is enabled on an interface, the switch can learn new addresses up to the maximum defined.

Answer: C E

Question 10

Refer to the exhibit. Which statement is true?

A. The Fa0/11 role confirms that SwitchA is the root bridge for VLAN 20.
B. VLAN 20 is running the Per VLAN Spanning Tree Protocol.
C. The MAC address of the root bridge is 0017.596d.1580.
D. SwitchA is not the root bridge, because not all of the interface roles are designated.

Answer: D

Explanation

Only non-root bridge can have root port. Fa0/11 is the root port so we can confirm this switch is not the root bridge -> A is not correct.

From the output we learn this switch is running Rapid STP, not PVST -> B is not correct.

0017.596d.1580 is the MAC address of this switch, not of the root bridge. The MAC address of the root bridge is 0017.596d.2a00 -> C is not correct.

All of the interface roles of the root bridge are designated. SwitchA has one Root port and 1 Alternative port so it is not the root bridge -> D is correct.

Question 12

A network administrator wants to ensure that only the server can connect to port Fa0/1 on a Catalyst switch. The server is plugged into the switch Fa0/1 port and the network administrator is about to bring the server online. What can the administrator do to ensure that only the MAC address of the server is allowed by switch port Fa0/1? (Choose two)

A. Configure port Fa0/1 to accept connections only from the static IP address of the server.
B. Employ a proprietary connector type on Fa0/1 that is incompatible with other host connectors.
C. Configure the MAC address of the server as a static entry associated with port Fa0/1.
D. Bind the IP address of the sewer to its MAC address on the switch to prevent other hosts from spoofing the server IP address.
E. Configure port security on Fa0/1 to reject traffic with a source MAC address other than that of the server.
F. Configure an access list on the switch to deny server traffic from entering any port other than Fa0/1.

Answer: C E

Explanation

We can”configure the MAC address of the server as a static entry associated with port Fa0/1″ with this command:

Switch(config-if)#switchport port-security mac-address sticky 0000.00AA.AAAA.AAAA

and “configure port security on Fa0/1 to reject traffic with a source MAC address other than that of the server” with these commands:

Switch(config-if)#switchport port-security maximum 1 (only allow 1 MAC address and that is the static MAC address)

Also we often define what will the switch do if the security is violated:

Switch(config-if)#switchport port-security violation shutdown

Question 13

The network security policy requires that only one host be permitted to attach dynamically to each switch interface. If that policy is violated, the interface should shut down. Which two commands must the network administrator configure on the 2950 Catalyst switch to meet this policy? (Choose two)

A. Switch1(config-if)#switchport port-security maximum 1
B. Switch1(config)#mac-address-table secure
C. Switch1(config)#access-list 10 permit ip host
D. Switch1(config-if)#switchport port-security violation shutdown
E. Switch1(config-if)#ip access-group 10

Answer: A D

Question 1

In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?

A. after broken links are re-established
B. in an improperly implemented redundant topology
C. when upper-layer protocols require high reliability
D. during high traffic periods
E. when a dual ring topology is in use

Answer: B

Explanation

If we connect two switches via 2 or more links and do not enable STP on these switches then a loop (which creates multiple copies of the same unicast frame) will occur. It is an example of an improperly implemented redundant topology.

Question 2

An administrator would like to configure a switch over a virtual terminal connection from locations outside of the local LAN. Which of the following are required in order for the switch to be configured from a remote location? (Choose two)

A. The switch must be configured with an IP address, subnet mask, and default gateway.
B. The switch must be connected to a router over a VLAN trunk.
C. The switch must be reachable through a port connected to its management VLAN.
D. The switch console port must be connected to the Ethernet LAN.
E. The switch management VLAN must be created and have a membership of at least one switch port.
F. The switch must be fully configured as an SNMP agent.

Answer: A C

Explanation

In order to remote access to a switch from outside of the local LAN (in a different subnet) we have to:

+ Configure an IP address on a VLAN on that switch, this VLAN is known as the management VLAN (it is usually VLAN 1)
+ Specify the default gateway for that switch so that it can send traffic to this gateway

Below shows an example of configuring remote access for a switch (suppose the management VLAN on the switch is 192.168.1.10/24 and the default-gateway IP address is 192.168.1.254)

Switch(config)#ip default-gateway 192.168.1.254
Switch(config)#interface vlan 1
Switch(config)#ip address 192.168.1.10 255.255.255.0
Switch(config)#no shutdown

Question 3

Refer to the exhibit. A junior network administrator was given the task of configuring port security on SwitchA to allow only PC_A to access the switched network through port fa0/1. If any other device is detected, the port is to drop frames from this device. The administrator configured the interface and tested it with successful pings from PC_A to RouterA, and then observes the output from these two show commands.

Which two of these changes are necessary for SwitchA to meet the requirements? (Choose two)

A. Port security needs to be globally enabled.
B. Port security needs to be enabled on the interface.
C. Port security needs to be configured to shut down the interface in the event of a violation.
D. Port security needs to be configured to allow only one learned MAC address.
E. Port security interface counters need to be cleared before using the show command.
F. The port security configuration needs to be saved to NVRAM before it can become active.

Answer: B D

Explanation

As we see in the output, the “Port Security” is in “Disabled” state (line 2 in the output). To enable Port security feature, we must enable it on that interface first with the command:

SwitchA(config-if)#switchport port-security

-> B is correct.

Also from the output, we learn that the switch is allowing 2 devices to connect to it (switchport port-security maximum 2) but the question requires allowing only PC_A to access the network so we need to reduce the maximum number to 1 -> D is correct.

Question 4

A company implements video conferencing over IP on their Ethernet LAN. The users notice that the network slows down, and the video either stutters or foils completely. What is the most likely reason for this?

A. minimum cell rate (MCR)
B. quality of service (QoS)
C. modulation
D. packet switching exchange (PSE)
E. reliable transport protocol (RTP)

Answer: B

Explanation

If the QoS is not configured correctly on the network (for example configure your network’s bandwidth below the bandwidth assigned by your ISP) can slow down all your traffic.

Question 8

Refer to the exhibit. Some 2950 series switches are connected to the conference area of the corporate headquarters network. The switches provide two to three jacks per conference room to host laptop connections for employees who visit the headquarters office. When large groups of employees come from other locations, the network administrator often finds that hubs have been connected to wall jacks in the conference area although the ports on the access layer switches were not intended to support multiple workstations.

What action could the network administrator take to prevent access by multiple laptops through a single switch port and still leave the switch functional for its intended use?

A. Configure static entries in the switch MAC address table to include the range of addresses used by visiting employees.
B. Configure an ACL to allow only a single MAC address to connect to the switch at one time.
C. Use the mac-address-table 1 global configuration command to limit each port to one source MAC address.
D. Implement Port Security on all interfaces and use the port-security maximum 1 command to limit port access to a single MAC address
E. Implement Port Security on all interfaces and use the port-security mac-address sticky command to limit access to a single MAC address
F. Implement Port Security at global configuration mode and use the port-security maximum 1 command to allow each switch only one attached hub

Answer: D

Explanation

The Port Security filters frames based on its MAC so it can effectively prevent people connecting to the switch via hubs.

Question 9

Which of the following statements are true regarding bridges and switches? (Choose 3)

A. Switches are primarily software based while bridges are hardware based.
B. Both bridges and switches forward Layer 2 broadcasts.
C. Bridges are frequently faster than switches.
D. Switches have a higher number of ports than most bridges.
E. Bridges define broadcast domains while switches define collision domains.
F. Both bridges and switches make forwarding decisions based on Layer 2 addresses.

Answer: B D F

Question 10

A network administrator must configure 200 switch ports to accept traffic from only the currently attached host devices. What would be the most efficient way to configure MAC-level security on all these ports?

A. Visually verify the MAC addresses and then telnet to the switches to enter the switchport-port security mac-address command.
B. Have end users e-mail their MAC addresses. Telnet to the switch to enter the switchport-port security mac-address command.
C. Use the switchport port-security MAC address sticky command on all the switch ports that have end devices connected to them.
D. Use show mac-address-table to determine the addresses that are associated with each port and then enter the commands on each switch for MAC address port-security.

Answer: C

Explanation

We can use the “interface range” command (for example “interface range FastEthernet 0/1 – 48″) to configure many ports as the same time and use the “port-security MAC address sticky” command (without a specific MAC address) to dynamically learn the attached MAC Address and place it into the switch’s running-configuration -> C is correct.

Which two of these changes are necessary for SwitchA to meet the requirements? (Choose two)

Answer: B D

Explanation

As we see in the output, the “Port Security” is in “Disabled” state (line 2 in the output). To enable Port security feature, we must enable it on that interface first with the command:

SwitchA(config-if)#switchport port-security

-> B is correct.

Question 4

A. minimum cell rate (MCR)
B. quality of service (QoS)
C. modulation
D. packet switching exchange (PSE)
E. reliable transport protocol (RTP)

Answer: B

Explanation

If the QoS is not configured correctly on the network (for example configure your network’s bandwidth below the bandwidth assigned by your ISP) can slow down all your traffic.

CCNA Switching Dumps

Question 1

Refer to the exhibit. The following commands are executed on interface fa0/1 of 2950Switch.

2950Switch(config-if)#switchport port-security
2950Switch(config-if)#switchport port-security mac-address sticky
2950Switch(config-if)#switchport port-security maximum 1

The Ethernet frame that is shown arrives on interface fa0/1. What two functions will occur when this frame is received by 2950Switch? (Choose two)

A. The MAC address table will now have an additional entry of fa0/1 FFFF.FFFF.FFFF.
B. Only host A will be allowed to transmit frames on fa0/1.
C. This frame will be discarded when it is received by 2950Switch.
D. All frames arriving on 2950Switch with a destination of 0000.00aa.aaaa will be forwarded out fa0/1.
E. Hosts B and C may forward frames out fa0/1 but frames arriving from other switches will not be forwarded out fa0/1.
F. Only frames from source 0000.00bb.bbbb, the first learned MAC address of 2950Switch, will be forwarded out fa0/1.

Answer: B D

Explanation

Please read the explanation at http://www.9tut.net/icnd2/icnd2-operations

Question 2

Which Cisco Catalyst feature automatically disables the port in an operational PortFast upon receipt of a BPDU?

A. BackboneFast
B. UplinkFast
C. Root Guard
D. BPDU Guard
E. BPDU Filter

Answer: D

Explanation

We only enable PortFast feature on access ports (ports connected to end stations). But if someone does not know he can accidentally plug that port to another switch and a loop may occur when BPDUs are being transmitted and received on these ports.

With BPDU Guard, when a PortFast receives a BPDU, it will be shut down to prevent a loop -> D is correct.

Question 3

Why will a switch never learn a broadcast address?

A. Broadcast frames are never sent to switches.
B. Broadcast addresses use an incorrect format for the switching table.
C. A broadcast address will never be the source address of a frame.
D. Broadcasts only use network layer addressing.
E. A broadcast frame is never forwarded by a switch.

Answer: C

Question 4

Which three statements accurately describe layer 2 Ethernet switches? (choose three)

A. Microsegmentation decreases the number of collisions on the network.
B. If a switch receives a frame for an unknown destination.it uses ARP to resolve the address.
C. Spanning Tree Protocol allows switches to automatically share vlan information.
D. In a property functioning network with redundant switched paths, each switched segment will contain one root bridge with all its ports in the forwarding state. All other switches in that broadcast domain will have only one root port.
E. Establishing vlans increases the number of broadcast domains.
F. Switches that are configured with vlans make forwarding decisions based on both layer 2 and layer 3 address information.

Answer: A D E

Question 5

Switch ports operating in which two roles will forward traffic according to the IEEE 802.1w standard? (Choose two)

A. alternate
B. backup
C. designated
D. disabled
E. root

Answer: C E

Explanation

IEEE 802.1w is the standard of Rapid Spanning Tree Protocol (RSTP). There are 5 port roles in this standard: Root port, Designated port, Alternative port, Backup port and Disabled port. In these 5 port roles, only Root port and Designated port can forward traffic.

Question 6

Select the action that results from executing these commands:

Switch(config-if)# switchport port-security
Switch(config-if)# switchport port-security mac-address sticky

A. A dynamically learned MAC address is saved in the startup-configuration file.
B. A dynamically learned MAC address is saved in the running-configuration file.
C. A dynamically learned MAC address is saved in the VLAN database.
D. Statically configured MAC addresses are saved in the startup-configuration file if frames from that address are received.
E. Statically configured MAC addresses are saved in the running-configuration file if frames from that address are received.

Answer: B

Explanation

The full syntax of the second command is:

switchport port-security mac-address sticky [MAC]

If we don’t specify the MAC address (like in this question) then the switch will dynamically learn the attached MAC Address and place it into your running-configuration -> B is correct.

Question 7

What is valid reason for a switch to deny port access to new devices when port security is enabled?

A. The denied MAC addresses have already been learned or configured on another secure interface in the same VLAN.
B. The denied MAC address are statically configured on the port.
C. The minimum MAC threshold has been reached.
D. The absolute aging times for the denied MAC addresses have expired.

Answer: A

Explanation

A security violation occurs in either of these situations:

* When the maximum number of secure MAC addresses is reached on a secure port and the source MAC address of the ingress traffic is different from any of the identified secure MAC addresses, port security applies the configured violation mode.

* If traffic with a secure MAC address that is configured or learned on one secure port attempts to access another secure port in the same VLAN, applies the configured violation mode.

From the second statement we can figure out A is the correct answer. But for your information we will discuss other answers as well.

Answer B is not correct because we can’t configured which MAC address will be denied. We can only configure which MAC is allowed.

We can only configure the maximum MAC threshold, not the minimum threshold -> C is not correct.

The aging times are only configured for allowed MAC addresses, not for denied MAC -> D is correct.

For your information about aging time:

When the aging type is configured with the absolute keyword, all the dynamically learned secure addresses age out when the aging time expires

This is how to configure the secure MAC address aging type on the port:

Router(config-if)# switchport port-security aging type absolute

and configure the aging time (aging time = 120 minutes)

Router(config-if)# switchport port-security aging time 120

When this command is used, all the dynamically learned secure addresses age out when the aging time expires

(Reference: http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/port_sec.html)

CCNA Switching Question

Question 1

Which of the following are true regarding bridges and switches? (Choose two)

A. Bridges are faster than switches because they have fewer ports.
B. A switch is a multiport bridge.
C. Bridges and switches learn MAC addresses by examining the source MAC address of each frame received.
D. A bridge will forward a broadcast but a switch will not.
E. Bridges and switches increase the size of a collision domain.

Answer: B C

Question 2

Which two commands correctly verily whether port security has been configured on port FastEthernet 0/12 on a switch? (Choose two)

A. SW1# show switchport port-security interface FastEthernet 0/12
B. SW1# show switchport port-secure interface FastEthernet 0/12
C. SW1# show port-security interface FastEthernet 0/12
D. SW1# show running-config

Answer: C D

Question 3

Assuming the default switch configuration which vlan range can be added modified and removed on a Cisco switch?

A. 2 through 1001
B. 1 through 1001
C. 1 through 1002
D. 2 through 1005

Answer: A

Question 4

Which set of commands is recommended to prevent the use of a hub in the access layer?

A.
switch(config-if)#switchport mode trunk
switch(config-if)#switchport port-security maximum 1

B.
switch(config-if)#switchport mode trunk
switch(config-if)#switchport port-security mac-address 1

C.
switch(config-if)#switchport mode access
switch(config-if)#switchport port-security maximum 1

D.
switch(config-if)#switchport mode access
switch(config-if)#switchport port-security mac-address 1

Answer: C

Explanation

Port security is only used on access port (which connects to hosts) so we need to set that port to “access” mode, then we need to specify the maximum number of hosts which are allowed to connect to this port -> C is correct.

Note: If we want to allow a fixed MAC address to connect, use the “switchport port-security mac-address <MAC address>” command.

Question 5

A Catalyst 2950 needs to be reconfigured. What steps will ensure that the old configuration is erased? (Choose three)

A. Erase flash.
B. Restart the switch.
C. Delete the VLAN database.
D. Erase the running configuration.
E. Erase the startup configuration.
F. Modify the configuration register.

Answer: B C E

Question 6

The network administrator has discovered that the power supply has failed on a switch in the company LAN and that the switch has stopped functioning. It has been replaced with a Cisco Catalyst 2950 series switch. What must be done to ensure that this new switch becomes the root bridge on the network?

A. Lower the bridge priority number.
B. Change the MAC address of the switch.
C. Increase the VTP revision number for the domain.
D. Lower the root path cost on the switch ports.
E. Assign the switch an IP address with the lowest value.

Answer: A

Question 7

Which two of these are characteristics of the 802.1Q protocol? (Choose two)

A. It is a layer 2 messaging protocol which maintains vlan configurations across network.
B. It includes an 8-bit field which specifies the priority of a frame.
C. It is used exclusively for tagging vlan frames and dose not address network reconvergence following switched network topology changes.
D. It modifies the 802.3 frame header and thus requires that the FCS be recomputed.
E. It is a trunking protocol capable of earring untagged frames.

Answer: D E

Explanation

IEEE 802.1Q is the networking standard that supports Virtual LANs (VLANs) on an Ethernet network. It is a protocol that allows VLANs to communicate with one another using a router. 802.1Q trunks support tagged and untagged frames.

If a switch receives untagged frames on a trunk port, it believes that frame is a part of the native VLAN. Also, frames from a native VLAN are not tagged when exiting the switch via a trunk port.

The 802.1q frame format is same as 802.3. The only change is the addition of 4 bytes fields. That additional header includes a field with which to identify the VLAN number. Because inserting this header changes the frame, 802.1Q encapsulation forces a recalculation of the original FCS field in the Ethernet trailer.

Note: Frame Check Sequence (FCS) is a four-octet field used to verify that the frame was received without loss or error. FCS is based on the contents of the entire frame.

Question 8

What are two advantages of Layer 2 Ethernet switches over hubs? (Choose two)

A. decreasing the number of collision domains
B. filtering frames based on MAC addresses
C. allowing simultaneous frame transmissions
D. increasing the size of broadcast domains
E. increasing the maximum length of UTP cabling between devices

Answer: B C

Explanation

Hub is considered a layer 1 device. When a packet arrives at one port, it is copied to the other ports without checking the content of that packet.

Switch operates at layer 2. When a packet arrives at one port, it checks in its database (based on MAC address) to see which port it should forward that packet out -> B is correct.

Remember that hubs can only communicate in half duplex mode, which means that a computer can only send data when it is not receiving. Switches can run in full duplex mode, which allows data to be sent and received at the same time. Switches effectively double the speed of the network when compared to hubs -> C is correct.

Switch increases the number of collision domains (which is better) -> A is not correct.

Switch does not have any effect on the size of broadcast domains. When using switch, the size of broadcast domains remain the same -> D is not correct.

Both hub and switch increase the maximum length of UTP cabling between devices so it is not an advantage of switch over hub -> E is not correct.

Question 9

Which command will show the MAC addresses of stations connected to switch ports?

A. show mac-address
B. show arp
C. show table
D. show switchport

Answer: B

Explanation

There is no “show mac-address” command. But notice the “show mac-address-table” and “show mac address-table” do exist.

If option A is “show mac-address-table” then both A & B are correct!

CCNA WAN Questions

Here you will find answers to WAN Questions

Question 1

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. 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 DF packets 0

Answer: C

Question :2

When troubleshooting a Frame Relay connection, what is the first step when performing a loopback test?

A. Set the encapsulation of the interface to HDLC.
B. Place the CSU/DSU in local-loop mode.
C. Enable local-loop mode on the DCE Frame Relay router.
D. Verify that the encapsulation is set to Frame Relay.

Answer: A

Explanation

The first thing when performing a loopback test on a Frame Relay connection is to reconfigure the encapsulation of the interface to HDLC protocol instead of Frame Relay protocol. The main reason is Frame Relay requires a pair of DCE/DTE which cannot be used in a loopback test.

For more information about steps of trouble shooting Frame Relay, please read: http://www.cisco.com/en/US/tech/tk713/tk237/technologies_tech_note09186a008014f8a7.shtml#topic20

For your information, below is a paragraph quoted from the above link:

“Serial0 is down, line protocol is down”

This output means you have a problem with the cable, channel service unit/data service unit (CSU/DSU), or the serial line. You need to troubleshoot the problem with a loopback test. To do a loopback test, follow the steps below:

1. Set the serial line encapsulation to HDLC and keepalive to 10 seconds. To do so, issue the commands encapsulation hdlc and keepalive 10 under the serial interface.
2. Place the CSU/DSU or modem in local loop mode. If the line protocol comes up when the CSU, DSU or modem is in local loopback mode (indicated by a “line protocol is up (looped)” message), it suggests that the problem is occurring beyond the local CSU/DSU. If the status line does not change states, there is possibly a problem in the router, connecting cable, CSU/DSU or modem. In most cases, the problem is with the CSU/DSU or modem.
3. Ping your own IP address with the CSU/DSU or modem looped. There should not be any misses. An extended ping of 0×0000 is helpful in resolving line problems since a T1 or E1 derives clock from data and requires a transition every 8 bits. B8ZS ensures that. A heavy zero data pattern helps to determine if the transitions are appropriately forced on the trunk. A heavy ones pattern is used to appropriately simulate a high zero load in case there is a pair of data inverters in the path. The alternating pattern (0×5555) represents a “typical” data pattern. If your pings fail or if you get cyclic redundancy check (CRC) errors, a bit error rate tester (BERT) with an appropriate analyzer from the telco is needed.
4. When you are finished testing, make sure you return the encapsulation to Frame Relay.

Question 3

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.

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.

Question 4

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.

Answer: B C

Question 5

The output of the show frame-relay pvc command shows ”PVC STATUS=INACTIVE”. What does this mean?

A. The PVC is configured correctly and is operating normally,but no data packets have been detected for more than five minutes.
B. The PVC is configured correctly, is operating normally and is no longer actively seeking the address the remote route,
C. The PVC is configured correctly, is operating normally and is waiting for interesting to trigger a call to the remote router.
D. The PVC is configured correctly on the local switch, but there is a problem on the remote end of the PVC.
E. The PVC is not configured on the switch.

Answer: D

Explanation

The PVC STATUS displays the status of the PVC. The DCE device creates and sends the report to the DTE devices. There are 4 statuses:

+ ACTIVE: the PVC is operational and can transmit data
+ INACTIVE: the connection from the local router to the switch is working, but the connection to the remote router is not available
+ DELETED: the PVC is not present and no LMI information is being received from the Frame Relay switch
+ STATIC: the Local Management Interface (LMI) mechanism on the interface is disabled (by using the “no keepalive” command). This status is rarely seen so it is ignored in some books.

Question 6

Which encapsulation type is a Frame Relay encapsulation type that is supported by Cisco routers?

A. Q933-A Annex A
B. IETF
C. ANSI Annex D
D. HDLC

Answer: B

Explanation

Cisco supports two Frame Relay encapsulation types: the Cisco encapsulation and the IETF Frame Relay encapsulation, which is in conformance with RFC 1490 and RFC 2427. The former is often used to connect two Cisco routers while the latter is used to connect a Cisco router to a non-Cisco router. You can test with your Cisco router when typing the command Router(config-if)#encapsulation frame-relay ? on a WAN link. Below is the output of this command (notice Cisco is the default encapsulation so it is not listed here, just press Enter to use it).

Note: Three LMI options are supported by Cisco routers are ansi, Cisco, and Q933a. They represent the ANSI Annex D, Cisco, and ITU Q933-A (Annex A) LMI types, respectively.

HDLC is a WAN protocol same as Frame-Relay and PPP so it is not a Frame Relay encapsulation type.

Wan Technologies

Question 1

The command frame-relay map ip 10.121.16.8 102 broadcast was entered on the router. Which of the following statements is true concerning thiscommand?

A: This command should be executed from the global configuration mode.

B: The IP address 10.121.16.8 is the local router port used to forward data.

C: 102 is the remote DLCI that will receive the information.

D: This command is required for all Frame Relay configurations.

E: The broadcast option allows packets, such as RIP updates, to be forwarded across the PVC.

Correct Answers: E

Explanation:

The command frame-relay map ip 10.121.16.8 102 broadcast means to mapping the distal IP 10.121.16.8 102 to the local DLCI 102. When the “broadcast” keyword is included, it turns Frame Relay network as a broadcast network, which can forward broadcasts

Question 2

Refer to the exhibit. 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 Answers: C

Explanation:

DLCI stands for Data Link Connection Identifier. DLCI values are used on Frame Relay interfaces to distinguish between different virtual circuits. DLCIs have local significance because the identifier references the point between the local router and the local Frame Relay switch to which the DLCI is connected.

Question 3

A default Frame Relay WAN is classified as what type of physical network?

A: point-to-point

B: broadcast multi-access

C: nonbroadcast multi-access

D: nonbroadcast multipoint

E: broadcast point-to-multipoint

Correct Answer: C

Explanation:

Non-Broadcast Multi-Access (NBMA) networks are types such as Frame Relay, X.25, and Asynchronous Transfer Mode (ATM). These networks allow for multi-access, but have no broadcast ability like Ethernet

Question 4

Which of the following are key characteristics of PPP? (Choose three.)

A: can be used over analog circuits

B: maps Layer 2 to Layer 3 address

C: encapsulates several routed protocols

D: supports IP only

E: provides error correction

Correct Answers: A C E

Explanation

Below is some more information about PPP:

PPP (Point-to-Point Protocol) allows authentication such as Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP) and multilink connections (allow several separate physical paths to appear to be one logical path at layer 3) and can be run over asynchronous and synchronous links.

PPP can work with numerous network layer protocols, including Internet Protocol (IP), Novell’s Internetwork Packet Exchange (IPX), NBF and AppleTalk.

PPP only supports error detection, not error correction so answer E should be understood as “provides error detection”. It is a mistake of this question.

Question 5

Which three Layer 2 encapsulation types would be used on a WAN rather than a LAN? (Choose three)

A: HDLC

B: Ethernet

C: Token Ring

D: PPP

E: FDDI

F: Frame Relay

Correct Answer: A D F

Question 6

Refer to the exhibit. What is the meaning of the term dynamic as displayed in the output of the show frame-relay map command shown?

A: The Serial0/0 interface is passing traffic.

B: The DLCI 100 was dynamically allocated by the router

C: The Serial0/0 interface acquired the IP address of 172.16.3.1 from a DHCP server

D: The DLCI 100 will be dynamically changed as required to adapt to changes in the Frame Relay cloud

E: The mapping between DLCI 100 and the end station IP address 172.16.3.1 was learned through Inverse ARP

Explanation

The term dynamic indicates that the DLCI number and the remote router IP address 172.16.3.1 are learned via the Inverse ARP process.

Inverse ARP is a technique by which dynamic mappings are constructed in a network, allowing a device such as a router to locate the logical network address and associate it with a permanent virtual circuit (PVC).

Correct Answer: E

Question 7

Which of the following describes the roles of devices in a WAN? (Choose three.)

A: A CSU/DSU terminates a digital local loop

B: A modem terminates a digital local loop

C: A CSU/DSU terminates an analog local loop

D: A modem terminates an analog local loop

E: A router is commonly considered a DTE device

F: A router is commonly considered a DCE device

Correct Answers: A D E

Question 8

How should a router that is being used in a Frame Relay network be configured to avoid split horizon issues from preventing routing updates?

A: Configure a separate sub-interface for each PVC with a unique DLCI and subnet assigned to the sub-interface

B: Configure each Frame Relay circuit as a point-to-point line to support multicast and broadcast traffic

C: Configure many sub-interfaces on the same subnet

D: Configure a single sub-interface to establish multiple PVC connections to multiple remote router interfaces

Correct Answer: A

Question 9

What can a network administrator utilize by using PPP Layer 2 encapsulation? (Choose three.)

A: VLAN support

B: compression

C: authentication

D: sliding windows

E: multilink support

F: quality of service

Correct Answers: B C E

Question 10

The Frame Relay network in the diagram is not functioning properly. What is the cause of the problem?

A: The Gallant router has the wrong LMI type configured

B: Inverse ARP is providing the wrong PVC information to the Gallant router

C: The S3 interface of the Steele router has been configured with the frame-relay encapsulation ietf command

D: The frame-relay map statement in the Attalla router for the PVC to Steele is not correct

E: The IP address on the serial interface of the Attalla router is configured incorrectly

Correct Answer: D

Explanation

At Attalla router, we find a deleted status but the next map statement indicates an active status, which if for Gallant. Therefore we can deduce the map statement for the PVC from Attalla to Steele is incorrect. Incorrect DLCI assignments that are configured normally shown up as “deleted” in the frame relay maps.

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