200-101 Free Practice Test

- (Topic 1)
Which three statements about RSTP are true? (Choose three.)

1. A. RSTP significantly reduces topology reconverging time after a link failure.
2. B. RSTP expands the STP port roles by adding the alternate and backup roles.
3. C. RSTP port states are blocking, discarding, learning, or forwarding.
4. D. RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.
5. E. RSTP also uses the STP proposal-agreement sequence.
6. F. RSTP uses the same timer-based process as STP on point-to-point links.

Correct Answer: ABD
http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cf a.shtml
Convergence
Cisco enhanced the original 802.1D specification with features such as Uplink Fast, Backbone Fast, and Port Fast to speed up the convergence time of a bridged network. The drawback is that these mechanisms are proprietary and need additional configuration.
Alternate and Backup Port Roles
These two port roles correspond to the blocking state of 802.1D. A blocked port is defined as not being the designated or root port. A blocked port receives a more useful BPDU than the one it sends out on its segment.
Remember that a port absolutely needs to receive BPDUs in order to stay blocked. RSTP introduces these two roles for this purpose.
Rapid Transition to Forwarding State
Rapid transition is the most important feature introduced by 802.1w. The legacy STA passively waited for the network to converge before it turned a port into the forwarding state. The achievement of faster convergence was a matter of tuning the conservative default parameters (forward delay and max_age timers) and often put the stability of the network at stake. The new rapid STP is able to actively confirm that a port can safely
transition to the forwarding state without having to rely on any timer configuration. There is now a real feedback mechanism that takes place between RSTP-compliant bridges. In order to achieve fast convergence on a port, the protocol relies upon two new variables: edge ports and link type.

- (Topic 6)
What are three reasons to collect Netflow data on a company network? (Choose three.)

1. A. To identify applications causing congestion
2. B. To authorize user network access
3. C. To report and alert link up / down instances
4. D. To diagnose slow network performance, bandwidth hogs, and bandwidth utilization
5. E. To detect suboptimal routing in the network
6. F. To confirm the appropriate amount of bandwidth that has been allocated to each Class of Service

Correct Answer: ADF

- (Topic 6)
Which feature does PPP use to encapsulate multiple protocols?

1. A. NCP
2. B. LCP
3. C. IPCP
4. D. IPXP

Correct Answer: A
Network Core Protocol (NCP) is the component that encapsulates and configures multiple network layer protocols.

- (Topic 2)
Which parameter or parameters are used to calculate OSPF cost in Cisco routers?

1. A. Bandwidth
2. B. Bandwidth and Delay
3. C. Bandwidth, Delay, and MTU
4. D. Bandwidth, MTU, Reliability, Delay, and Load

Correct Answer: A
http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094e9e.sht ml#t6
OSPF Cost
The cost (also called metric) of an interface in OSPF is an indication of the overhead required to send packets across a certain interface. The cost of an interface is inversely proportional to the bandwidth of that interface. A higher bandwidth indicates a lower cost. There is more overhead (higher cost) and time delays involved in crossing a 56k serial line than crossing a 10M Ethernet line. The formula used to calculate the cost is:
Cost= 10000 0000/bandwidth in bps
For example, it will cost 10 EXP8/10 EXP7 = 10 to cross a 10M Ethernet line and will cost
10 EXP8/1544000 =64 to cross a T1 line. By default, the cost of an interface is calculated based on the bandwidth; you can force the cost of an interface with the ip ospf cost
interface sub configuration mode command.

- (Topic 1)
Which three statements are typical characteristics of VLAN arrangements? (Choose three.)

1. A. A new switch has no VLANs configured.
2. B. Connectivity between VLANs requires a Layer 3 device.
3. C. VLANs typically decrease the number of collision domains.
4. D. Each VLAN uses a separate address space.
5. E. A switch maintains a separate bridging table for each VLAN.
6. F. VLANs cannot span multiple switches.

Correct Answer: BDE
By default, all ports on a new switch belong to VLAN 1 (default & native VLAN). There are also some well-known VLANs (for example: VLAN 1002 for fddi-default; VLAN 1003 for token-ring…) configured by default -> A is not correct.
To communicate between two different VLANs we need to use a Layer 3 device like router or Layer 3 switch -> B is correct.
VLANs don’t affect the number of collision domains, they are the same -> C is not correct. Typically, VLANs increase the number of broadcast domains.We must use a different network (or sub-network) for each VLAN. For example we can use 192.168.1.0/24 for VLAN 1, 192.168.2.0/24 for VLAN 2 -> D is correct.
A switch maintains a separate bridging table for each VLAN so that it can send frame to ports on the same VLAN only. For example, if a PC in VLAN 2 sends a frame then the switch look-ups its bridging table and only sends frame out of its ports which belong to VLAN 2 (it also sends this frame on trunk ports) -> E is correct.
We can use multiple switches to expand VLAN -> F is not correct.