CCNA 2 2

Refer to the exhibit. A network administrator is verifying the configuration of inter-VLAN routing. Users complain that PC2 cannot communicate with PC1. Based on the output, what is the possible cause of the problem?

• • Gi0/0 is not configured as a trunk port.

• • The command interface GigabitEthernet0/0.5 was entered incorrectly.

• • There is no IP address configured on the interface Gi0/0.

• • The no shutdown command is not entered on subinterfaces.

• • The encapsulation dot1Q 5 command contains the wrong VLAN. 

Refer to the exhibit. A network administrator is configuring inter-VLAN routing on a network. For now, only one VLAN is being used, but more will be added soon. What is the missing parameter that is shown as the highlighted question mark in the graphic?

• • It identifies the subinterface.

• • It identifies the VLAN number.

• • It identifies the native VLAN number.

• • It identifies the type of encapsulation that is used.

• • It identifies the number of hosts that are allowed on the interface.

What network attack seeks to create a DoS for clients by preventing them from being able to obtain a DHCP lease?

• • IP address spoofing

• • DHCP starvation

• • CAM table attack

• • DHCP spoofing

Answer explanation

Explanation: DCHP starvation attacks are launched by an attacker with the intent to create a DoS for DHCP clients. To accomplish this goal, the attacker uses a tool that sends many DHCPDISCOVER messages in order to lease the entire pool of available IP addresses, thus denying them to legitimate hosts.

Refer to the exhibit. If the IP addresses of the default gateway router and the DNS server are correct, what is the configuration problem?

• • The DNS server and the default gateway router should be in the same subnet.

• • The IP address of the default gateway router is not contained in the excluded address list.

• • The default-router and dns-server commands need to be configured with subnet masks.

• • The IP address of the DNS server is not contained in the excluded address list.

Answer explanation

Explanation: In this configuration, the excluded address list should include the address that is assigned to the default gateway router. So the command should be ip dhcp excluded-address 192.168.10.1 192.168.10.9.

Refer to the exhibit. A network administrator has added a new subnet to the network and needs hosts on that subnet to receive IPv4 addresses from the DHCPv4 server.
What two commands will allow hosts on the new subnet to receive addresses from the DHCP4 server? (Choose two.)

• • R1(config-if)# ip helper-address 10.1.0.254

• • R2(config-if)# ip helper-address 10.2.0.250

• • R1(config-if)# ip helper-address 10.2.0.250

• • R1(config)# interface G0/1

• • R1(config)# interface G0/0

Answer explanation

Explanation: You need the router interface that is connected to the new subnet and the dhcp server address.
The ip helper-address command is used to configure a router to be a DHCPv4 relay. The command should be placed on the interface facing the DHCPv4 clients. When the command is applied on the router interface, the interface will receive DHCPv4 broadcast messages and forward them as unicast to the IP address of the DHCPv4 server.

What protocol or technology uses source IP to destination IP as a load-balancing mechanism?

• • VTP

• • EtherChannel

• • DTP

• • STP

What protocol should be disabled to help mitigate VLAN attacks?

• • DTP

• • STP

• • ARP

• • CDP

What protocol or technology requires switches to be in server mode or client mode?

• • DTP

• • EtherChannel

• • STP

• • VTP

What are two reasons a network administrator would segment a network with a Layer 2 switch? (Choose two.)

• • to create fewer collision domains

• • to enhance user bandwidth

• • to eliminate virtual circuits

• • to isolate traffic between segments

• • to isolate ARP request messages from the rest of the network

Answer explanation

Explanation: A switch has the ability of creating temporary point-to-point connections between the directly-attached transmitting and receiving network devices. The two devices have full-bandwidth full-duplex connectivity during the transmission.

What command will enable a router to begin sending messages that allow it to configure a link-local address without using an IPv6 DHCP server?

• • the ip routing command

• • the ipv6 route ::/0 command

• • the ipv6 unicast-routing command

• • a static route

Answer explanation

Explanation: To enable IPv6 on a router you must use the ipv6 unicast-routing global configuration command or use the ipv6 enable interface configuration command. This is equivalent to entering ip routing to enable IPv4 routing on a router when it has been turned off. Keep in mind that IPv4 is enabled on a router by default. IPv6 is not enabled by default.