Q1. - (Topic 5)
Refer to the exhibit.
After configuring two interfaces on the HQ router, the network administrator notices an error message. What must be done to fix this error?
A. The serial interface must be configured first.
B. The serial interface must use the address 192.168.1.2
C. The subnet mask of the serial interface should be changed to 255.255.255.0
D. The subnet mask of the FastEthernet interface should be changed to 255.255.255.240
E. The address of the FastEthernet interface should be changed to 192.168.1.66
Answer: D
Explanation:
The IP address 192.168.1.17 255.255.255.0 specifies that the address is part of the 192.168.1.0/24 subnet
24 mask bits = 255.255.255.0 28 mask bits = 255.255.255.240 192.168.1.0/24 subnet has a host range of 192.168.1.1 to 192.168.1.254 (0 being network and 255 being broadcoast) 192.168.1.17/28 subnet has a host range of 192.168.1.17 to 192.168.1.30 (16 being network and 31 being broadcast) 192.168.1.65/28 subnet has a host range of 192.168.1.65 - 192.168.1.78 (64 being network and 79 being broadcast)
if fa0/0 was left as /24, you can see that the host range includes the host range of 192.168.1.64/28 which conflicts. Simply speaking, you can't overlap the subnets. By changing the subnet mask of fa0/0 to 255.255.255.240, these networks would no longer overlap.
Q2. - (Topic 1)
Which three statements are true about the operation of a full-duplex Ethernet network? (Choose three.)
A. There are no collisions in full-duplex mode.
B. A dedicated switch port is required for each full-duplex node.
C. Ethernet hub ports are preconfigured for full-duplex mode.
D. In a full-duplex environment, the host network card must check for the availability of the network media before transmitting.
E. The host network card and the switch port must be capable of operating in full-duplex mode.
Answer: A,B,E
Explanation:
Half-duplex Ethernet is defined in the original 802.3 Ethernet and Cisco says you only use one wire pair with a digital signal running in both directions on the wire. It also uses the CSMA/CD protocol to help prevent collisions and to permit retransmitting if a collision does occur. If a hub is attached to a switch, it must operate in half-duplex mode because the end stations must be able to detect collisions. Half-duplex Ethernet—typically 10BaseT—is only about 30 to 40 percent efficient as Cisco sees it, because a large 10BaseT network will usually only give you 3- to 4Mbps—at most. Full-duplex Ethernet uses two pairs of wires, instead of one wire pair like half duplex. Also, full duplex uses a point-to-point connection between the transmitter of the transmitting device and the receiver of the receiving device, which means that with full-duplex data transfer, you get a faster data transfer compared to half duplex. And because the transmitted data is sent on a different set of wires than the received data, no collisions occur. The reason you don’t need to worry about collisions is because now Full-duplex Ethernet is like a freeway with multiple lanes instead of the single-lane road provided by half duplex. Full-duplex Ethernet is supposed to offer 100 percent efficiency in both directions; this means you can get 20Mbps with a 10Mbps Ethernet running full duplex, or 200Mbps for FastEthernet.
Q3. - (Topic 3)
What is the default administrative distance of the OSPF routing protocol?
A. 90
B. 100
C. 110
D. 120
E. 130
F. 170
Answer: C
Explanation:
Default Distance Value Table This table lists the administrative distance default values of the protocols that Cisco supports: If the administrative distance is 255, the router does not believe the source of that route and does not install the route in the routing table.
Q4. - (Topic 1)
Refer to the exhibit.
A network device needs to be installed in the place of the icon labeled Network Device to accommodate a leased line attachment to the Internet. Which network device and interface configuration meets the minimum requirements for this installation?
A. a router with two Ethernet interfaces
B. a switch with two Ethernet interfaces
C. a router with one Ethernet and one serial interface
D. a switch with one Ethernet and one serial interface
E. a router with one Ethernet and one modem interface
Answer: C
Explanation:
Only a router can terminate a leased line attachment access circuit, and only a router can connect two different IP networks. Here, we will need a router with two interfaces, one serial connection for the line attachment and one Ethernet interface to connect to the switch on the LAN.
Q5. - (Topic 3)
Why do large OSPF networks use a hierarchical design? (Choose three.)
A. to decrease latency by increasing bandwidth
B. to reduce routing overhead
C. to speed up convergence
D. to confine network instability to single areas of the network
E. to reduce the complexity of router configuration
F. to lower costs by replacing routers with distribution layer switches
Answer: B,C,D
Explanation:
OSPF implements a two-tier hierarchical routing model that uses a core or backbone tier known as area zero (0). Attached to that backbone via area border routers (ABRs) are a number of secondary tier areas.
The hierarchical approach is used to achieve the following:
. Rapid convergence because of link and/or switch failures
. Deterministic traffic recovery
. Scalable and manageable routing hierarchy, reduced routing overhead.
Q6. - (Topic 3)
Which three approaches can be used while migrating from an IPv4 addressing scheme to an IPv6 scheme? (Choose three)
A. static mapping of IPv4 address to IPv6 addresses
B. configuring IPv4 tunnels between IPv6 islands
C. use DHCPv6 to map IPv4 addresses to IPv6 addresses
D. use proxying and translation (NAT-PT) to translate IPv6 packets into IPv4 packets
E. configure IPv6 directly
F. enable dual-stack routing
Answer: B,D,F
Explanation:
Connecting IPv6 islands with tunnels An IPv6 island is a network made of IPv6 links directly connected by IPv6 routers. In the early days of IPv6 deployment, there are many IPv6 islands. IPv6 in IPv4 tunnels are used to connect those islands together. In each island, one (or more) dual stack routers are designated to encapsulate and decapsulate IPv6 packets within IPv4 packets. Different mechanisms have been developed to manage tunnels: automatic tunnels3, configured tunnels3, tunnel brokers3, 6over43, 6to43,... Reference 2: http://www.petri.co.il/ipv6-transition.htm Network Address Translation - Protocol Translation (NAT-PT) The NAT-PT method enables the ability to either statically or dynamically configure a translation of a IPv4 network address into an IPv6 network address and vice versa. For those familiar with more typically NAT implementations, the operation is very similar but includes a protocol translation function. NAT-PT also ties in an Application Layer Gateway (ALG) functionality that converts Domain Name System (DNS) mappings between protocols.
Dual Stack The simplest approach when transitioning to IPv6 is to run IPv6 on all of the devices that are currently running IPv4. If this is something that is possible within the organizational network, it is very easy to implement. However, for many organizations, IPv6 is not supported on all of the IPv4 devices; in these situations other methods must be considered.
Reference: http://www.opus1.com/ipv6/howdoitransitiontoipv6.html
Q7. - (Topic 7)
Two hosts are attached to a switch with the default configuration. Which statement about the configuration is true?
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.
Answer: A
Explanation: IP routing must be enables to allow the two hosts to communicate with each other with default configuration. http://www.cisco.com/c/en/us/support/docs/lan-switching/inter-vlan-routing/41860-howto-L3-intervlanrouting.html
Q8. - (Topic 7)
Which statement about static routes is true?
A. The source interface can be configured to make routing decisions.
B. A subnet mask is entered for the next-hop address.
C. The subnet mask is 255.255 255.0 by default
D. The exit interface can be specified to indicate where the packets will be routed.
Answer: D
Explanation:
Static routing can be used to define an exit point from a router when no other routes are available or necessary. This is called a default route.
Q9. - (Topic 3)
Refer to the exhibit.
Which command would you use to configure a static route on Router1 to network 192.168.202.0/24 with a nondefault administrative distance?
A. router1(config)#ip route 1 192.168.201.1 255.255.255.0 192.168.201.2
B. router1(config)#ip route 192.168.202.0 255.255.255.0 192.168.201.2 1
C. router1(config)#ip route 5 192.168.202.0 255.255.255.0 192.168.201.2
D. router1(config)#ip route 192.168.202.0 255.255.255.0 192.168.201.2 5
Answer: D
Explanation:
The default AD for a static route is 1. To change this, configure a different value to be used as the AD at the very end of the “ip route” statement.
Q10. - (Topic 3)
Refer to the exhibit.
When running OSPF, what would cause router A not to form an adjacency with router B?
A. The loopback addresses are on different subnets.
B. The values of the dead timers on the routers are different.
C. Route summarization is enabled on both routers.
D. The process identifier on router A is different than the process identifier on router B.
Answer: B
Explanation:
To form an adjacency (become neighbor), router A & B must have the same Hello interval, Dead interval and AREA numbers