# [Free] 2018(July) Ensurepass Cisco 100-105 Dumps with VCE and PDF 81-90

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2018 July Cisco Official New Released 100-105

Cisco Interconnecting Cisco Networking Devices Part 1 (ICND1 v3.0)

#### Question No: 81 – (Topic 3)

An administrator is working with the 192.168.4.0 network, which has been subnetted with a

/26 mask. Which two addresses can be assigned to hosts within the same subnet? (Choose two.)

A. 192.168.4.61

B. 192.168.4.63

C. 192.168.4.67

D. 192.168.4.125

E. 192.168.4.128

F. 192.168.4.132

Increment: 64 (/26 = 11111111.11111111.11111111.11000000)

The IP 192.168.4.0 belongs to class C. The default subnet mask of class C is /24 and it has been subnetted with a /26 mask so we have 2(26-24) = 22 = 4 sub-networks:

1st subnet: 192.168.4.0 (to 192.168.4.63)

2nd subnet: 192.168.4.64 (to 192.168.4.127)

3rd subnet: 192.168.4.128 (to 192.168.4.191)

4th subnet: 192.168.4.192 (to 192.168.4.225)

In all the answers above, only answer C and D are in the same subnet. Therefore only IPs in this range can be assigned to hosts.

#### Question No: 82 – (Topic 3)

Given an IP address of 192.168.1.42 255.255.255.248, what is the subnet address?

A. 192.168.1.8/29 B. 192.168.1.32/27 C. 192.168.1.40/29 D. 192.168.1.16/28 E. 192.168.1.48/29

248 mask uses 5 bits (1111 1000)

42 IP in binary is (0010 1010)

The base subnet therefore is the lowest binary value that can be written without changing the output of an AND operation of the subnet mask and IP…

1111 1000 AND

0010 1010 equals

0010 1000 – which is .40

/24 is standard class C mask.

#### Question No: 83 – (Topic 3)

Refer to the exhibit.

PC1 pings PC2. What three things will CORE router do with the data that is received from PC1? (Choose three.)

1. The data frames will be forwarded out interface FastEthernet0/1 of CORE router.

2. The data frames will be forwarded out interface FastEthernet1/0 of CORE router.

3. CORE router will replace the destination IP address of the packets with the IP address of PC2.

4. CORE router will replace the MAC address of PC2 in the destination MAC address of the frames.

5. CORE router will put the IP address of the forwarding FastEthernet interface in the place of the source IP address in the packets.

6. CORE router will put the MAC address of the forwarding FastEthernet interface in the place of the source MAC address.

The router will forward the frames out the interface toward the destination – B is correct. Since the router will has the end station already in it’s MAC table as see by the “show arp” command, it will replace the destination MAC address to that of PC2 – D is correct.

The router will then replace the source IP address to 172.16.40.1 – E is correct.

#### Question No: 84 – (Topic 3)

An administrator must assign static IP addresses to the servers in a network. For network 192.168.20.24/29, the router is assigned the first usable host address while the sales server is given the last usable host address.

Which of the following should be entered into the IP properties box for the sales server?

Default Gateway: 192.168.20.9

Default Gateway: 192.168.20.1

Default Gateway: 192.168.20.25

Default Gateway: 192.168.20.17

Default Gateway: 192.168.20.25

With network 192.168.20.24/29 we have:

Increment: 8 (/29 = 255.255.255.248 = 11111000 for the last octet) Network address: 192.168.20.24 (because 24 = 8 * 3)

Therefore the first usable IP address is 192.168.20.25 (assigned to the router) and the last usable IP address is 192.168.20.30 (assigned to the sales server). The IP address of the router is also the default gateway of the sales server.

#### Question No: 85 – (Topic 3)

Identify the four valid IPv6 addresses. (Choose four.)

A. ::

B. ::192:168:0:1

C. 2000::

D. 2001:3452:4952:2837::

E. 2002:c0a8:101::42

#### Question No: 86 – (Topic 3)

Which command is used to display the collection of OSPF link states?

2. show ip ospf lsa database

3. show ip ospf neighbors

4. show ip ospf database

The “show ip ospf database” command displays the link states. Here is an example: Here is the lsa database on R2.

R2#show ip ospf database

OSPF Router with ID (2.2.2.2) (Process ID 1) Router Link States (Area 0)

10.4.4.4 10.4.4.4 776 0x80000004 0x005643 1

111.111.111.111 111.111.111.111 755 0x80000005 0x0059CA 2

133.133.133.133 133.133.133.133 775 0x80000005 0x00B5B1 2

10.2.2.3 133.133.133.133 812 0x80000001 0x004BA9

10.4.4.1 111.111.111.111 755 0x80000001 0x007F16

10.4.4.3 133.133.133.133 775 0x80000001 0x00C31F

#### Question No: 87 – (Topic 3)

Refer to the exhibit.

Why are two OSPF designated routers identified on Core-Router?

1. Core-Router is connected to more than one multi-access network.

2. The router at 208.149.23.130 is a secondary DR in case the primary fails.

3. Two router IDs have the same OSPF priority and are therefore tied for DR election

4. The DR election is still underway and there are two contenders for the role.

OSPF elects one DR per multi-access network. In the exhibit there are two DR so there must have more than one multi-access network.

#### Question No: 88 – (Topic 3)

Which three approaches can be used while migrating from an IPv4 addressing scheme to an IPv6 scheme? (Choose three)

2. configuring IPv4 tunnels between IPv6 islands

4. use proxying and translation (NAT-PT) to translate IPv6 packets into IPv4 packets

5. configure IPv6 directly

6. enable dual-stack routing

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

#### Question No: 89 – (Topic 3)

OSPF routing uses the concept of areas. What are the characteristics of OSPF areas? (Choose Three.)

1. Each OSPF area requires a loopback interface to be configured.

2. Areas may be assigned any number from 0 to 65535.

3. Area 0 is called the backbone area.

4. Hierarchical OSPF networks do not require multiple areas.

5. Multiple OSPF areas must connect to area 0.

6. Single area OSPF networks must be configured in area 1.

Definition of OSPF areas: An OSPF network may be structured, or subdivided, into routing areas to simplify administration and optimize traffic and resource utilization. Areas are identified by 32-bit numbers, expressed either simply in decimal, or often in octet-based dot-decimal notation, familiar from IPv4 address notation.

See discussion following Cisco Learning discussion. https://learningnetwork.cisco.com/message/90832

#### Question No: 90 – (Topic 3)

Which IOS command is used to initiate a login into a VTY port on a remote router?

2. router# telnet

3. router# trace

4. router# ping

5. router(config)# line vty 0 5