Q111. - (Topic 8)
Which destination IP address can a host use to send one message to multiple devices across different subnets?
Explanation: Multicast is a networking protocol where one host can send a message to a special multicast IP address and one or more network devices can listen for and receive those messages.
Multicast works by taking advantage of the existing IPv4 networking infrastructure, and it does so in something of a weird fashion. As you read, keep in mind that things are a little
confusing because multicast was "shoe-horned" in to an existing technology.
For the rest of this article, let's use the multicast IP address of 18.104.22.168. We'll not worry about port numbers yet, but make a mental note that they are used in multicast. We'll discuss that later.
Q112. - (Topic 5)
You have been asked to come up with a subnet mask that will allow all three web servers to be on the same network while providing the maximum number of subnets. Which network address and subnet mask meet this requirement?
A. 192.168.252.0 255.255.255.252
B. 192.168.252.8 255.255.255.248
C. 192.168.252.8 255.255.255.252
D. 192.168.252.16 255.255.255.240
E. 192.168.252.16 255.255.255.252
A subnet mask of 255.255.255.248 will allow for up to 6 hosts to reside in this network. A subnet mask of 255.255.255.252 will allow for only 2 usable IP addresses, since we cannot
use the network or broadcast address.
Q113. - (Topic 5)
What are three features of the IPv6 protocol? (Choose three.)
A. optional IPsec
C. no broadcasts
D. complicated header
An important feature of IPv6 is that it allows plug and play option to the network devices by allowing them to configure themselves independently. It is possible to plug a node into an IPv6 network without requiring any human intervention. This feature was critical to allow network connectivity to an increasing number of mobile devices. This is accomplished by autoconfiguration.
IPv6 does not implement traditional IP broadcast, i.e. the transmission of a packet to all hosts on the attached link using a special broadcast address, and therefore does not define broadcast addresses. In IPv6, the same result can be achieved by sending a packet to the link-local all nodes multicast group at address ff02::1, which is analogous to IPv4 multicast to address 22.214.171.124.
Q114. - (Topic 8)
Which MAC protocol sets a random timer to reattempt communication?
A. IEEE 802.1x
Q115. - (Topic 5)
Which three statements about HSRP operation are true? (Choose three.)
A. The virtual IP address and virtual MA+K44C address are active on the HSRP Master router.
B. The HSRP default timers are a 3 second hello interval and a 10 second dead interval.
C. HSRP supports only clear-text authentication.
D. The HSRP virtual IP address must be on a different subnet than the routers' interfaces on the same LAN.
E. The HSRP virtual IP address must be the same as one of the router's interface addresses on the LAN.
F. HSRP supports up to 255 groups per interface, enabling an administrative form of load balancing.
The virtual MAC address of HSRP version 1 is 0000.0C07.ACxx, where xx is the HSRP group number in hexadecimal based on the respective interface. For example, HSRP group 10 uses the HSRP virtual MAC address of 0000.0C07.AC0A. HSRP version 2 uses a virtual MAC address of 0000.0C9F.FXXX (XXX: HSRP group in hexadecimal).
Q116. - (Topic 5)
In GLBP, which router will respond to client ARP requests?
A. The active virtual gateway will reply with one of four possible virtual MAC addresses.
B. All GLBP member routers will reply in round-robin fashion.
C. The active virtual gateway will reply with its own hardware MAC address.
D. The GLBP member routers will reply with one of four possible burned in hardware addresses.
One disadvantage of HSRP and VRRP is that only one router is in use, other routers must wait for the primary to fail because they can be used. However, Gateway Load Balancing Protocol (GLBP) can use of up to four routers simultaneously. In GLBP, there is still only one virtual IP address but each router has a different virtual MAC address. First a GLBP group must elect an Active Virtual Gateway (AVG). The AVG is responsible for replying ARP requests from hosts/clients. It replies with different virtual MAC addresses that correspond to different routers (known as Active Virtual Forwarders – AVFs) so that clients can send traffic to different routers in that GLBP group (load sharing).
Q117. - (Topic 3)
Which commands are required to properly configure a router to run OSPF and to add network 192.168.16.0/24 to OSPF area 0? (Choose two.)
A. Router(config)# router ospf 0
B. Router(config)# router ospf 1
C. Router(config)# router ospf area 0
D. Router(config-router)# network 192.168.16.0 0.0.0.255 0
E. Router(config-router)# network 192.168.16.0 0.0.0.255 area 0
F. Router(config-router)# network 192.168.16.0 255.255.255.0 area 0
In the router ospf command, the ranges from 1 to 65535 so o is an invalid number -> but To configure OSPF, we need a wildcard in the “network” statement, not a subnet mask. We also need to assgin an area to this process ->.
Q118. - (Topic 5)
Refer to the exhibit.
A network administrator is adding two new hosts to SwitchA. Which three values could be used for the configuration of these hosts? (Choose three.)
A. host A IP address: 192.168.1.79
B. host A IP address: 192.168.1.64
C. host A default gateway: 192.168.1.78
D. host B IP address: 192.168.1.128
E. host B default gateway: 192.168.1.129
F. host B IP address: 192.168.1.190
It’s a “router-on-a-stick” configuration. Which means each host in the VLAN must corresponds with the VLAN configured on the sub-interfaces.
VLAN 10 is configured on fa0/0.10 and VLAN 20 on fa0/0.20. So each hosts in VLAN 10 must use fa0/0.10 IP address as their default gateway, each hosts must also be in the same subnet as fa0/0.10 IP – same with hosts in VLAN 20.
So find out the usable IP addresses on each sub-interfaces – for 192.168.1.78 /27: 192.168.1.65 – .94 and for 192.168.1.130 /26: 192.168.1.128 – .190.
Host A (using port 6 – VLAN 10) must use IP 192.168.1.79, default gateway 192.168.1.78. Host B (using port 9 – VLAN 20) must use IP 192.168.1.190, default gateway
Q119. - (Topic 4)
Which two statements about using the CHAP authentication mechanism in a PPP link are true? (Choose two.)
A. CHAP uses a two-way handshake.
B. CHAP uses a three-way handshake.
C. CHAP authentication periodically occurs after link establishment.
D. CHAP authentication passwords are sent in plaintext.
E. CHAP authentication is performed only upon link establishment.
F. CHAP has no protection from playback attacks.
CHAP is an authentication scheme used by Point to Point Protocol (PPP) servers to validate the identity of remote clients. CHAP periodically verifies the identity of the client by using a three-way handshake. This happens at the time of establishing the initial link (LCP), and may happen again at any time afterwards. The verification is based on a shared secret (such as the client user's password).
Q120. - (Topic 8)
Which component of the routing table ranks routing protocols according to their preferences?
A. administrative distance
B. next hop
D. routing protocol code
Administrative distance - This is the measure of trustworthiness of the source of the route. If a router learns about a destination from more than one routing protocol, administrative distance is compared and the preference is given to the routes with lower administrative distance. In other words, it is the believability of the source of the route.