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- CCNA Routing and Switching 200-105
16.
A switch's G0/1 interface, a trunk that supports VLANs 1-10, has autonegotiated a
speed of 100 Mbps. The switch currently has all default settings for STP. Which of
the following actions results in the switch using an STP cost of 19 for that interface in
VLAN 3? (Choose two answers.)
- A.spanning-tree cost 19
- B.spanning-tree port-cost 19
- C.spanning-tree vlan 3 port-cost 19
- D.Adding no configuration
- Answer & Explanation
- Report
Answer : [A and D]
Explanation :
Explanation :
| The spanning-tree cost 19 command sets the cost for all VLANs on that interface unless the cost is set by a spanning-tree cost command that lists the VLAN ID. The two commands with a port-cost parameter are incorrect; the correct keyword is simply cost. Finally, Cisco switches choose the default cost based on the current speed, not the interface's fastest possible speed. So, this interface, running at 100 Mbps, already defaults to the IEEE default cost for 100 Mbps, or 19. |
17.
An engineer configures a switch to put interfaces G0/1 and G0/2 into the same Layer 2
EtherChannel. Which of the following terms is used in the configuration commands?
- A.EtherChannel
- B.PortChannel
- C.Ethernet-Channel
- D.Channel-group
- Answer & Explanation
- Report
Answer : [D]
Explanation :
Explanation :
| IOS uses the channel-group configuration command to create an EtherChannel. Then, the term etherchannel is used in the show etherchannel command, which displays the status of the channel. The output of this show command then names the channel a PortChannel. The only answer that is not used somewhere in IOS to describe this multilink channel is Ethernet-Channel. |
18.
Examine the following first seven lines of output from the show spanning-tree command on a Cisco switch:
SW1# show spanning-tree vlan 5 VLAN0005 Spanning tree enabled protocol rstp Root ID Priority 32773 Address 1833.9d7b.0e80 Cost 15 Port 25 (GigabitEthernet0/1) Hello Time 2 sec Max Age 20 sec Forward Delay 15 secWhich of the following answers is true about the switch on which this command output was gathered? (Choose two answers.)
- A.The root switch's MAC address is 1833.9d7b.0e80 and the local switch is the root.
- B.The local switch's MAC address is 1833.9d7b.0e80 and it is not the root.
- C.This switch uses STP and not RSTP.
- D.This switch uses RSTP.
- Answer & Explanation
- Report
Answer : [A],[D]
Explanation :
Explanation :
| First, regarding the listed MAC address of 1833.9d7b.0e80, the first group of messages listed at the beginning of the output of the show spanning-tree command lists information about the root switch, not the local switch. Second, the “protocol rstp” near the top of the output positively identifies that the switch is using RSTP, as configured with the spanning-tree mode rapid-pvst global configuration command. |
19.
The following output shows the last lines of output of a show spanning-tree command extracted from a Cisco switch running IOS:
SW1# show spanning-tree vlan 10 ! lines omitted Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- ----------------------- Fa0/1 Desg FWD 100 128.1 P2p Edge Fa0/2 Desg FWD 19 128.2 Shr Gi0/1 Desg FWD 4 128.25 P2p Gi0/2 Root FWD 4 128.26 P2pThe answers all mention an interface and the state listed in the Type column of the output, along with a reason why that port should be listed as that type of STP port. Which answers list what could be a correct reason for the interface to be listed as that type of STP port? (Choose two answers.)
- A.Fa0/1 is P2p Edge because of the spanning-tree rstp edge interface subcommand.
- B.Fa0/2 is Shr because Fa0/2 uses half duplex.
- C.Gi0/1 is P2p because it is a VLAN trunk.
- D.Gi0/2 is P2p because the switch had no reason to make it Shr or P2p Edge.
- Answer & Explanation
- Report
Answer : [B and D]
Explanation :
Explanation :
|
This question requires that you work through the reasons why a port is listed
as a particular type of STP port per the Type column in the output of the show
spanning-tree vlan 10 command. To begin, keep in mind that a port must have
PortFast enabled to be listed as an edge port. That configuration requires either the spanning-tree portfast interface subcommand or through setting the switch to use PortFast as a default with the spanning-tree portfast default global command. Answer choice A shows a type that includes “edge” and the reason listed has nothing to do with PortFast, so that answer is incorrect. For the other incorrect answer, C, the trunking status of a port does not impact the STP Type as listed in the output. Answer B is correct because any port that is using half duplex, either through negotiation or by configuration, is considered to be a shared port, as noted with “Shr” in the type column. Answer D is correct because if a switch has no reason to make a port act as a shared port, or as an edge port, the switch treats it as a point-to-point port. |
20.
Which of the following VTP modes allow VLANs to be configured on a switch?
(Choose two answers.)
- A.Client
- B.Server
- C.Transparent
- D.Dynamic
- Answer & Explanation
- Report
Answer : [B, C]
Explanation :
Explanation :
| VTP has three modes: server, client, and transparent. Only server and transparent mode switches can be used to configure VLANs; that is, to create the VLAN, delete the VLAN, and assign a VLAN a name. Client mode switches cannot configure VLANs. Also, there is no such mode as dynamic mode. |
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