CCNA – STP Questions

Question 1

Which three statements about RSTP are true? (choose three)
A. RSTP significantly reduces topology reconverging time after a link failure.
B. RSTP expends the STP port roles by adding the alternate and backup roles.
C. RSTP port states are blocking, discarding, learning, or forwarding.
D. RSTP also uses the STP proposal-agreement sequence.
E. RSTP use the same timer-based process as STP on point-to-point links.
F. RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

Answer: A B F

Question 2

Which two states are the port states when RSTP has converged? (choose two)
A. blocking
B. learning
C. disabled
D. forwarding
E. listening

Answer: A D

Explanation

RSTP only has 3 port states that are discarding, learning and forwarding. When RSTP has converged there are only 2 port states left: discarding and forwarding but the answers don’t mention about discarding state so blocking state (answer A) may be considered the best alternative answer.

Question 3

Which command enables RSTP on a switch?
A. spanning-tree mode rapid-pvst
B. spanning-tree uplinkfast
C. spanning-tree backbonefast
D. spanning-tree mode mst

Answer: A

Question 4

At which layer of the OSI model is RSTP used to prevent loops?
A. data link
B. network
C. physical
D. transport

Answer: A

Question 5

Refer to the exhibit. Given the output shown from this Cisco Catalyst 2950, what is the most likely reason that interface FastEthernet 0/10 is not the root port for VLAN 2?
Switch# show spanning-tree interface fastethernet0/10

A. This switch has more than one interface connected to the root network segment in VLAN 2.
B. This switch is running RSTP while the elected designated switch is running 802.1d Spanning Tree.
C. This switch interface has a higher path cost to the root bridge than another in the topology.
D. This switch has a lower bridge ID for VLAN 2 than the elected designated switch.

Answer: C

Question 6

Which two of these statements regarding RSTP are correct? (Choose two)
A. RSTP cannot operate with PVST+.
B. RSTP defines new port roles.
C. RSTP defines no new port states.
D. RSTP is a proprietary implementation of IEEE 802.1D STP.
E. RSTP is compatible with the original IEEE 802.1D STP.

Answer: B E

Question 7

Refer to the exhibit. Each of these four switches has been configured with a hostname, as well as being configured to run RSTP. No other configuration changes have been made. Which three of these show the correct RSTP port roles for the indicated switches and interfaces? (Choose three)

A. SwitchA, Fa0/2, designated
B. SwitchA, Fa0/1, root
C. SwitchB, Gi0/2, root
D. SwitchB, Gi0/1, designated
E. SwitchC, Fa0/2, root
F. SwitchD, Gi0/2, root

Answer: A B F

Explanation

The question says “no other configuration changes have been made” so we can understand these switches have the same bridge priority. Switch C has lowest MAC address so it will become root bridge and 2 of its ports (Fa0/1 & Fa0/2) will be designated ports -> E is incorrect.
Because SwitchC is the root bridge so the 2 ports nearest SwitchC on SwitchA (Fa0/1) and SwitchD (Gi0/2) will be root ports -> B and F are correct.
Now we come to the most difficult part of this question: SwitchB must have a root port so which port will it choose? To answer this question we need to know about STP cost and port cost.
In general, “cost” is calculated based on bandwidth of the link. The higher the bandwidth on a link, the lower the value of its cost. Below are the cost values you should memorize:

Link speed	Cost
10Mbps	100
100Mbps	19
1 Gbps	4

SwitchB will choose the interface with lower cost to the root bridge as the root port so we must calculate the cost on interface Gi0/1 & Gi0/2 of SwitchB to the root bridge. This can be calculated from the “cost to the root bridge” of each switch because a switch always advertises its cost to the root bridge in its BPDU. The receiving switch will add its local port cost value to the cost in the BPDU.
One more thing to notice is that a root bridge always advertises the cost to the root bridge (itself) with an initial value of 0.
Now let’s have a look at the topology again

SwitchC advertises its cost to the root bridge with a value of 0. Switch D adds 4 (the cost value of 1Gbps link) and advertises this value (4) to SwitchB. SwitchB adds another 4 and learns that it can reach SwitchC via Gi0/1 port with a total cost of 8. The same process happens for SwitchA and SwitchB learns that it can reach SwitchC via Gi0/2 with a total cost of 23 -> Switch B chooses Gi0/1 as its root port -> D is not correct.
Now our last task is to identify the port roles of the ports between SwitchA & SwitchB. It is rather easy as the MAC address of SwitchA is lower than that of SwitchB so Fa0/2 of SwitchA will be designated port while Gi0/2 of SwitchB will be alternative port -> A is correct but C is not correct.
Below summaries all the port roles of these switches:

+ DP: Designated Port (forwarding state)
+ RP: Root Port (forwarding state)
+ AP: Alternative Port (blocking state)

Question 8

Which two protocols are used by bridges and/or switches to prevent loops in a layer 2 network? (Choose two)
A. 802.1d
B. VTP
C. 802.1q
D. STP
E. SAP

Answer: A D

Question 9

Which switch would STP choose to become the root bridge in the selection process?
A. 32768: 11-22-33-44-55-66
B. 32768: 22-33-44-55-66-77
C. 32769: 11-22-33-44-55-65
D. 32769: 22-33-44-55-66-78

Answer: A

Question 10

Refer to the topology shown in the exhibit. Which ports will be STP designated ports if all the links are operating at the same bandwidth? (Choose three)

A. Switch A – Fa0/0
B. Switch A – Fa0/1
C. Switch B – Fa0/0
D. Switch B – Fa0/1
E. Switch C – Fa0/0
F. Switch C – Fa0/1

Answer: B C D

Explanation

First by comparing their MAC addresses we learn that switch B will be root bridge as it has lowest MAC. Therefore all of its ports are designated ports -> C & D are correct.
On the link between switch A & switch C there must have one designated port and one non-designated (blocked) port. We can figure out which port is designated port by comparing their MAC address again. A has lower MAC so Fa0/1 of switch A will be designated port while Fa0/1 of switch C will be blocked ->  B is correct.

CCNA – Hotspot

Hotspot Routing Question

Question 1:

If the router R1 has a packet with a destination address 192.168.1.255, what describes the operation of the network?
A – R1 will forward the packet out all interfaces
B – R1 will drop this packet because it is not a valid IP address
C – As R1 forwards the frame containing this packet, Sw-A will add 192.168.1.255 to its MAC table
D – R1 will encapsulate the packet in a frame with a destination MAC address of FF-FF-FF-FF-FF-FF
E – As R1 forwards the frame containing this packet, Sw-A will forward it ti the device assigned the IP address of 192.168.1.255

Answer: B

Question 2:

Users on the 192.168.1.0/24 network must access files located on the Server 1. What route could be configured on router R1 for file requests to reach the server?
A – ip route 0.0.0.0 0.0.0.0 s0/0/0
B – ip route 0.0.0.0 0.0.0.0 209.165.200.226
C – ip route 209.165.200.0 255.255.255.0 192.168.1.250
D – ip route 192.168.1.0 255.255.255.0 209.165.100.250

Answer: A

Quetion 3:

When a packet is sent from Host 1 to Server 1, in how many different frames will the packet be encapsulated as it is sent across the internetwork?
A – 0
B – 1
C – 2
D – 3
E – 4

Answer: C or D(depending on your understand, please read the comments to understand why)

Question 4:

What must be configured on the network in order for users on the Internet to view web pages located on Web Server 2?
A – On router R2,configure a default static route to the 192.168.1.0 network
B – On router r2, configure DNS to resolve the URL assigned to Web Server 2 to the 192.168.1.10 address
C – On router R1, configure NAT to translate an address on the 209.165.100.0/24 network to 192.168.1.10
D – On router R1, configure DHCP to assign a registered IP address on the 209.165.100.0/24 network to Web Server 2

Answer: C

Question 5:

The router address 192.168.1.250 is the default gateway for both the Web Server 2 and Host 1. What is the correct subnet mask for this network?
A – 255.255.255.0
B – 255.255.255.192
C – 255.255.255.250
D – 255.255.255.252

Answer: A

Hotspot Frame-relay Question

(In the old days, this question was a multi-choice question but Cisco upgraded it into a lab-sim question. Therefore, instead of listing all the configuration as above, you have to type show frame-relay map and show running-config to get its configuration)
Note: If you are not sure about Frame-Relay, please read my Frame Relay tutorial.

Question 1:

What destination Layer 2 address will be used in the frame header containing a packet for host 172.30.0.4?
A – 704
B – 196
C – 702
D – 344

Answer: C

Question 2:

A static map to the S-AMER location is required. Which command should be used to create this map?
A – frame-relay map ip 172.30.0.3 704 broadcast
B – frame-relay map ip 172.30.0.3 196 broadcast
C – frame-relay map ip 172.30.0.3 702 broadcast
D – frame-relay map ip 172.30.0.3 344 broadcast

Answer: B

Question 3:

Which connection uses the default encapsulation for serial interfaces on Cisco routers?
A – The serial connection to the MidEast branch office
B – The serial connection to the DeepSouth branch office
C – The serial connection to the NorthCentral branch office
D – The serial connection to the Multinational Core

Answer: A

Question 4:

If required, what password should be configured on the router in the MidEast branch office to allow a connection to be established with the Dubai router?
A – No password is required
B – Enable
C – Scr
D – Telnet
E – Console

Answer: A or D (because maybe there are 2 versions of this question, depending on the output of “show running-config” command, please read the explanation below)
Explanation
This question is not clear for a long time but now maybe the trick was solved. What Cisco wants to ask is the word used as password, not the type of connection, so in the exam you might see some strange words for answers like “En8ble”, “T1net”, “C0nsole”. All you have to do is to use the command “show running-config” as wx4 mentioned below to find the answer.
wx4 commented:
Q4: if password required which?
in my example it was connection to North!
How to figure out which pw is required?
#show running-config
1. check the interface to the router you need connection to. If there is “ppp authentication” you need a password!
2. you will find the password on the top of your running-config output
check the area:
username North password c0nsole
username xxxxx yyyyy
username…
in my case it was c0nsole, in your case it can be no password needed or a different password.
If you are still not clear, please read anton‘s comment:
A big question I noticed here was about the FR Lab regarding the password. You have to perform a show running-config and look for USERNAME and PASSWORD.
i.e.
username South_Router password c0nsol3
username North_Router password t31net
Obviously this has to be en PPP encapsulation, if asked for a posible password for SOUTH_ROUTER you pick c0nsol3, and for NORTH_ROUTER you pick t31net. If you’re running HDLC, i would pick “no password is required”.

CCNA – VTP Questions

Question 1

Refer to the exhibit. After SwitchB was added to the network, VLAN connectivity problems started to occur. What caused this problem?

A. Both switches are in server mode in the same domain.
B. The revision number of SwitchB was higher than the revision number of SwitchA.
C. SwitchA was not rebooted prior to adding SwitchB to the network.
D. V2-mode is not enabled.
E. VTP pruning is not activated, so the new paths in the network have not been recalculated.

Answer: B

Explanation

SwitchB has the same VTP Domain Name with SwitchA and it has a higher Configuration Revision number (7 > 1) so it will overwrite VLAN information of SwitchA. Because SwitchB is a new switch so its VLAN information is different from SwitchA -> VLAN connectivity problem occurs.

Question 2

A network administrator is explaining VTP configuration to a new technician. What should the network administrator tell the new technician about VTP configuration? (Choose three)
A. A switch in the VTP client mode cannot update its local VLAN database.
B. A trunk link must be configured between the switches to forward VTP updates.
C. A switch in the VTP server mode can update a switch in the VTP transparent mode.
D. A switch in the VTP transparent mode will forward updates that it receives to other switches.
E. A switch in the VTP server mode only updates switches in the VTP client mode that have a higher VTP revision number.
F. A switch in the VTP server mode will update switches in the VTP client mode regardless of the configured VTP domain membership.

Answer: A B D

Question 3

What are two benefits of using VTP in a switching environment? (Choose two)
A.It allows switches to read frame tags.
B. It allows ports to be assigned to VLANs automatically.
C. It maintains VLAN consistency across a switched network.
D. It allows frames from multiple VLANs to use a single interface.
E. It allows VLAN information to be automatically propagated throughout the switching environment.

Answer: C E

Question 4

What is the name of the VTP mode of operation that enables a switch to forward only VTP advertisements while still permitting the editing of local VLAN information?
A. server
B. client
C. tunnel
D.transparent

Answer: D

Question 5

Which VTP mode is capable of creating only local VLANs and does not synchronize with other switches in the VTP domain?
A. client
B. dynamic
C. server
D. static
E. transparent

Answer: E

Question 6

An administrator is unsuccessful in adding VLAN 50 to a switch. While troubleshooting the problem, the administrator views the output of the show vtp status command, which is displayed in the graphic. What commands must be issued on this switch to add VLAN 50 to the database? (Choose two)

A. Switch(config-if)# switchport access vlan 50
B. Switch(vlan)#vtp server
C. Switch(config)# config-revision 20
D. Switch(config)#vlan 50 name Tech
E. Switch(vlan)# vlan 50
F. Switch(vlan)# switchport trunk vlan 50

Answer: B E

Explanation

First we notice that the “VTP Operating Mode” of this switch is “Client”. In this mode we can’t add new VLAN so we must change to “Server” mode -> B is correct.
Now we can add a new VLAN, E is the correct configuration for adding a new VLAN.

Question 7

To configure the VLAN trunking protocol to communicate VLAN information between two switches, what two requirements must be met? (Choose two)
A. Each end of the trunk line must be set to IEEE 802.1E encapsulation.
B. The VTP management domain name of both switches must be set the same.
C. All ports on both the switches must be set as access ports.
D. One of the two switches must be configured as a VTP server.
E. A rollover cable is required to connect the two switches together.
F. A router must be used to forward VTP traffic between VLANs.

Answer: B D

Explanation

In Cisco switches there are two encapsulations: 802.1q and ISL so we can set two ends to ISL instead -> A is not correct.
The ports between two switches must be set to trunk ports so that they can exchange VLAN information through VTP -> C is not correct.
To connect two switches we can use cross-over cable or straight-through cable (because modern Cisco switches can “auto-sense”) but not rollover cable -> E is not correct.
To forward traffic in the same VLAN (between two or more switches) we can use switches only. If we want to forward VTP traffic between different VLANs we can use either a router or a Layer 3 switch -> F is not correct.
Two switches can only communicate when they are set to the same VTP domain name (and the same VTP password) -> B is correct.
One of the two switches must be set to VTP Server so that it can create VTP updates and advertise its VLAN information.

Question 8

Which statements describe two of the benefits of VLAN Trunking Protocol? (Choose two)
A. VTP allows routing between VLANs.
B. VTP allows a single switch port to carry information to more than one VLAN.
C. VTP allows physically redundant links while preventing switching loops.
D. VTP simplifies switch administration by allowing switches to automatically share VLAN configuration information.
E. VTP helps to limit configuration errors by keeping VLAN naming consistent across the VTP domain.
F. VTP enhances security by preventing unauthorized hosts from connecting to the VTP domain.

Answer: D E

Explanation

The main purposes of VTP are to simplify switch administration and limit VLAN configuration errors by allowing switches to automatically share VLAN configuration information. It doesn’t require the administrator to go to every switch to configure VLANs.
Maybe you will feel F is also a correct answer but it is not true because VTP only enhances security by preventing unauthorized switches (not hosts) from connecting to the VTP domain (by configuring a VTP domain name & VTP password). An unauthorized host can easily use the network cable of an authorized host to access the network.

Question 9

What are two results of entering the Switch(config)#vtp mode client command on a Catalyst switch? (Choose two)
A. The switch will ignore VTP summary advertisements.
B. The switch will forward VTP summary advertisements.
C. The switch will process VTP summary advertisements.
D. The switch will originate VTP summary advertisements.
E. The switch will create, modify and delete VLANs for the entire VTP domain.

Answer: B C

Question 10

Refer to the exhibit. The show vtp status command is executed at a switch that is generating the exhibited output. Which statement is true for this switch?

A. The switch forwards its VLAN database to other switches in the ICND VTP domain.
B. The configuration revision number increments each time the VLAN database is updated,
C. The switch forwards VTP updates that are sent by other switches in the ICND domain,
D. The VLAN database is updated when VTP information is received from other switches.

Answer: C

Explanation

In Transparent mode switch just forwards update sent by other switches without reading it. It doesn’t update its VLAN database so the Configuration Revision doesn’t increase.