- Which switching method duplicates the first six bytes of a frame before making a switching decision?
Show (Hide) Explanation/ReferenceIn cut-through switching, the switch copies into its memory only the destination MAC address (first six bytes of the frame) of the frame. After processing these first six bytes, the switch had enough information to make a forwarding decision and move the frame to the appropriate switchport. This switching method is faster than store-and-forward switching method.
- A. fragment-free switching
- B. cut-through switching*
- C. store-and-forward switching
- D. ASIC switching
In store-and-forward switching, the switch copies each complete Ethernet frame into the switch memory and computes a Cyclic Redundancy Check (CRC) for errors. If a CRC error is found, the Ethernet frame is dropped. If no CRC error is found then that frame is forwarded.
- Refer to the exhibit. Which of these statements correctly describes the state of the switch once the boot process has been completed?
Show (Hide) Explanation/ReferenceFrom the output we notice that the administrator has just shut down Interface Vlan1, which is the default VLAN so no one can access it remotely (like telnet) -> B is correct.
- A. As FastEthernet0/12 will be the last to come up, it will not be blocked by STP.
- B. Remote access management of this switch will not be possible without configuration change.*
- C. More VLANs will need to be created for this switch.
- D. The switch will need a different IOS code in order to support VLANs and STP.
Answer A is not correct as STP calculation does not depend on which port comes up first or last. STP recalculates when there is a change in the network.
A normal switch can operate without VLAN -> C is not correct.
This IOS does support VLAN because it has VLAN 1 on it -> D is not correct.
- The network administrator normally establishes a Telnet session with the switch from host A. The administrator‟s attempt to establish a connect via Telnet to the switch from host B fails, but pings from host B to other two hosts are successful. What is the issue for this problem?
Show (Hide) Explanation/ReferenceHost A (172.19.1.1) and the management IP address of the Switch (172.19.1.250) are in the same subnet so telnet from host A to the switch can be successful even if a default gateway is not set on host A.
- A. Host B and the switch need to be in the same subnet.
- B. The switch needs an appropriate default gateway assigned.*
- C. The switch interface connected to the router is down.
- D. Host B need to be assigned an IP address in vlan 1.
But host B (172.19.32.2) and the management IP address of the Switch (172.19.1.250) are not in the same subnet. Therefore packets from host B must reach the router Fa0/0.32 interface before forwarding to the switch. But when the switch replies, it does not know how to send packets so an appropriate default gateway must be assigned on the switch (to Fa0/0.32 – 172.19.32.254).
Answer A is not correct because even when host B & the switch are in the same subnet, they cannot communicate because of different VLANs.
Answer C is not correct as host B can ping other two hosts.
Answer D is not correct because host B always belongs to VLAN 32 so assigning an IP address in VLAN 1 does not solve the problem.
- The network administrator cannot connect to Switch1 over a Telnet session, although the hosts attached to Switch1 can ping the interface Fa0/0 of the router. Given the information in the graphic and assuming that the router and Switch2 are configured properly, which of the following commands should be issued on Switch1 to correct this problem?
- A. Switch1 (config)# line con0
Switch1 (config-line)# password cisco
- B. Switch1 (config)# interface fa0/1
Switch 1(config-if)# ip address 192.168.24.3 255.255.255.0
- C. Switch1 (config)# ip default-gateway 192.168.24.1*
- D. Switch1 (config)# interface fa0/1
Switch 1(config-if)# duplex full
Switch 1(config-if)# speed 100
- E. Switch1 (config)# interface fa0/1
Switch 1(config-if)# switchport mode trunk
- A. Switch1 (config)# line con0
- Which command can you use to set the hostname on a switch?
- A. switch-mdf-c1(config)#hostname switch-mdf1*
- B. switch-mdf-c1>hostname switch-mdf1
- C. switch-mdf-c1#hostname switch-mdf1
- D. switch-mdf-c1(config-if)#hostname switch-mdf1
- Refer to the exhibit. What is the effect of the given configuration?
Switch#configuration terminal Switch#interface VLAN 1 Switch(config-if)#ip address 192.168.2.2 255.255.255.0 Switch(config-if)#end
Show (Hide) Explanation/ReferenceIn the configuration above, the “no shutdown” command was missing so interface Vlan 1 is still inactive. Notice that only the loopback command does not need the “no shutdown” command to work.
- A. It configures an inactive switch virtual interface.*
- B. It configures an active management interface.
- C. It configures the native VLAN.
- D. It configures the default VLAN.
- Which statement about switch access ports is true?
Show (Hide) Explanation/ReferenceA VLAN does not need to be assigned to any port -> B is not correct.
- A. They drop packets with 802.1Q tags.*
- B. A VLAN must be assigned to an access port before it is created.
- C. They can receive traffic from more than one VLAN with no voice support
- D. By default, they carry traffic for VLAN 10.
An access port can only receive traffic from one VLAN -> C is not correct.
If not assigned to a specific VLAN, an access port carries traffic for VLAN 1 by default -> D is not correct.
An access port will drop packets with 802.1Q tags -> A is correct. Notice that 802.1Q tags are used to packets moving on trunk links.
- Which feature allows a device to use a switch port that is configured for half-duplex to access the network?
Show (Hide) Explanation/ReferenceCarrier Sense Multiple Access with Collision Detection (CSMA/CD) is the LAN access method used in Ethernet. When a device wants to gain access to the network, it checks to see if the network is free. If the network is not free, the device waits a random amount of time before retrying. If the network is free and two devices access the line at exactly the same time, their signals collide. When the collision is detected, they both back off and wait a random amount of time before retrying.
- A. CSMA/CD*
- B. IGMP
- C. port security
- D. split horizon
CSMA/CD is used with devices operating in half-duplex mode only. CSMA/CD helps devices connecting to half-duplex switch ports operate correctly.
- Which option is a invalid hostname for a switch?
Show (Hide) Explanation/ReferenceThe “!” is a special character which is not allowed in the hostname of Cisco device.
- A. 5witch-Cisco
- B. Switch-Cisco!*
- C. 5witchCisc0
- D. SwitchCisc0
- Which statement about unicast frame forwarding on a switch is true?
- A. The TCAM table stores destination MAC addresses
- B. If the destination MAC address is unknown, the frame is flooded to every port that is configured in the same VLAN except on the port that it was received on.*
- C. The CAM table is used to determine whether traffic is permitted or denied on a switch
- D. The source address is used to determine the switch port to which a frame is forwarded
- Two hosts are attached to a switch with the default configuration. Which statement about the configuration is true?
Show (Hide) Explanation/ReferenceAll ports on a Layer 2 switch are in the same broadcast domain. Only router ports separate broadcast domains.
- A. IP routing must be enabled to allow the two hosts to communicate.
- B. The two hosts are in the same broadcast domain.*
- C. The switch must be configured with a VLAN to allow the two hosts to communicate.
- D. Port security prevents the hosts from connecting to the switch.