100-105 | What Tested 100-105 dumps Is?

Q1. Refer to the exhibit.

The network administrator is testing connectivity from the branch router to the newly installed application server. What is the most likely reason for the first ping having a success rate of only 60 percent?

A. The network is likely to be congested, with the result that packets are being intermittently dropped.

B. The branch router had to resolve the application server MAC address.

C. There is a short delay while NAT translates the server IP address.

D. A routing table lookup delayed forwarding on the first two ping packets.

E. The branch router LAN interface should be upgraded to FastEthernet.

Answer: B

Explanation:

Initially the MAC address had to be resolved, but once it is resolved and is in the ARP table of the router, pings go through immediately.

Q2. A network administrator cannot connect to a remote router by using SSH. Part of the show interfaces command is shown.

router#show interfaces

Serial0/1/0 is up, line protocol is down

At which OSI layer should the administrator begin troubleshooting?

A. physical

B. data link

C. network

D. transport

Answer: B

Explanation:

https://learningnetwork.cisco.com/thread/12389

I think the indication here is "Serial 0 is up, line protocol is down". What causes this indication? Correct me if I am wrong. When you have this indication, a cable unplugged is

not a correct answer. If you check the output of your "show interface serial 0" command again, you should notice it as "Serial 0 is down, line protocol is down. Under the "show ip int brief" you should see status = down and protocol = down as opposed to up, down. Because you disconnected the cable, layer 1 will go down, which is indicated by the serial 0 down status. The line protocol status is for layer 2. So, a cable unplugged is not a correct answer to "Serial 0 is up, line protocol is down". Up/down means that the physical layer is OK, but there is a problem with the data link link (line protocol).

Q3. R1 is configured with the default configuration of OSPF. From the following list of IP addresses configured on R1, which address will the OSPF process select as the router ID?

A. 192.168.0.1

B. 172.16.1.1

C. 172.16.2.1

D. 172.16.2.225

Answer: A

Explanation:

The Router ID (RID) is an IP address used to identify the router and is chosen using the following sequencE.

+ The highest IP address assigned to a loopback (logical) interface. + If a loopback interface is not defined, the highest IP address of all active router's physical interfaces will be chosen.

+ The router ID can be manually assigned

In this case, because a loopback interface is not configured so the highest active IP address 192.168.0.1 is chosen as the router ID.

Q4. What two things does a router do when it forwards a packet? (Choose two.)

A. switches the packet to the appropriate outgoing interfaces

B. computes the destination host address

C. determines the next hop on the path

D. updates the destination IP address

E. forwards ARP requests

Answer: A,C

Explanation:

A primary function of a router is to forward packets toward their destination. This is accomplished by using a switching function, which is the process used by a router to accept a packet on one interface and forward it out of another interface. A key responsibility of the switching function is to encapsulate packets in the appropriate data link frame type for the outgoing data link and determining the next hop device to send the frame to.

Q5. The ip helper-address command does what?

A. assigns an IP address to a host

B. resolves an IP address from a DNS server

C. relays a DHCP request across networks

D. resolves an IP address overlapping issue

Answer: C

Explanation:

http://cisconet.com/tcpip/dhcp/107-how-to-use-ip-helper-address-to-connect-remote-dhcp- server.html

When the DHCP client sends the DHCP request packet, it doesnu2021t have an IP address. So it uses the all-zeroes address, 0.0.0.0, as the IP source address. And it doesnu2021t know how to reach the DHCP server, so it uses a general broadcast address, 255.255.255.255, for the destination.

So the router must replace the source address with its own IP address, for the interface that received the request. And it replaces the destination address with the address specified in the ip helper-address command. The client deviceu2021s MAC address is included in the payload of the original DHCP request packet, so the router doesnu2021t need to do anything to ensure that the server receives this information. The router then relays the DHCP request to the DHCP server.

Q6. If an Ethernet port on a router was assigned an IP address of 172.16.112.1/20, what is the maximum number of hosts allowed on this subnet?

A. 1024

B. 2046

C. 4094

D. 4096

E. 8190

Answer: C

Explanation:

Each octet represents eight bits. The bits, in turn, represent (from left to right): 128, 64, 32 , 16 , 8, 4, 2, 1

Add them up and you get 255. Add one for the all zeros option, and the total is 256. Now, take away one of these for the network address (all zeros) and another for the broadcast address (all ones). Each octet represents 254 possible hosts. Or 254 possible

networks. Unless you have subnet zero set on your network gear, in which case you could conceivably have 255.

The CIDR addressing format (/20) tells us that 20 bits are used for the network portion, so the maximum number of networks are 2^20 minus one if you have subnet zero enabled, or minus 2 if not.

You asked about the number of hosts. That will be 32 minus the number of network bits, minus two. So calculate it as (2^(32-20))-2, or (2^12)-2 = 4094

Q7.

What is the subnet broadcast address of the LAN connected to Router1?

A. 192.168.8.15

B. 192.168.8.31

C. 192.168.8.63

D. 192.168.8.127

Answer: A

Explanation:

The IP address assigned to FA0/1 is 192.168.8.9/29, making 192.168.8.15 the broadcast address.

Q8. Refer to the exhibit.

The enterprise has decided to use the network address 172.16.0.0. The network administrator needs to design a classful addressing scheme to accommodate the three subnets, with 30, 40, and 50 hosts, as shown. What subnet mask would accommodate this network?

A. 255.255.255.192

B. 255.255.255.224

C. 255.255.255.240

D. 255.255.255.248

E. 255.255.255.252

Answer: A

Explanation:

Subnet mask A i.e. 255.255.255.192 with CIDR of /26 which means 64 hosts per subnet which are sufficient to accommodate even the largest subnet of 50 hosts.

Q9. Which protocol uses a connection-oriented service to deliver files between end systems?

A. TFTP

B. DNS

C. FTP

D. SNMP

E. RIP

Answer: C

Explanation:

TCP is an example of a connection-oriented protocol. It requires a logical connection to be

established between the two processes before data is exchanged. The connection must be maintained during the entire time that communication is taking place, then released afterwards. The process is much like a telephone call, where a virtual circuit is established-

-the caller must know the person's telephone number and the phone must be answered-- before the message can be delivered.

TCP/IP is also a connection-oriented transport with orderly release. With orderly release, any data remaining in the buffer is sent before the connection is terminated. The release is accomplished in a three-way handshake between client and server processes. The connection-oriented protocols in the OSI protocol suite, on the other hand, do not support orderly release. Applications perform any handshake necessary for ensuring orderly release.

Examples of services that use connection-oriented transport services are telnet, rlogin, and ftp.

Q10. Refer to the exhibit.

The host in Kiev sends a request for an HTML document to the server in Minsk. What will be the source IP address of the packet as it leaves the Kiev router?

A. 10.1.0.1

B. 10.1.0.5

C. 10.1.0.6

D. 10.1.0.14

E. 10.1.1.16

F. 10.1.2.8

Answer: E

Explanation:

Although the source and destination MAC address will change as a packet traverses a network, the source and destination IP address will not unless network address translation (NAT) is being done, which is not the case here.