EnsurePass
Exam Dumps
100-105 Dumps VCE and PDF
2019 100-105 Dumps VCE and PDF
QUESTION 121
Which statement is true?
A. |
An IPv6 address is 64 bits long and is represented as hexadecimal characters. |
B. |
An IPv6 address is 32 bits long and is represented as decimal digits. |
C. |
An IPv6 address is 128 bits long and is represented as decimal digits. |
D. |
An IPv6 address is 128 bits long and is represented as hexadecimal characters. |
Correct Answer: D
Explanation:
http://www.cisco.com/en/US/technologies/tk648/tk872/technologies_white_paper0900aecd 8026003d.pdf
One of the key advantages IPv6 brings is the exponentially larger address space. The following will outline the basic address architecture of IPv6.
128-bit-long addresses
Represented in hexadecimal format:
Uses CIDR principles: prefix/prefix length
x:x:x:x:x:x:x:x, where x is a 16-bit hex field
The last 64 bits are used for the interface ID
QUESTION 122
Which statement describes the process ID that is used to run OSPF on a router?
A. |
It is globally significant and is used to represent the AS number. |
B. |
It is locally significant and is used to identify an instance of the OSPF database. |
C. |
It is globally significant and is used to identify OSPF stub areas. |
D. |
It is locally significant and must be the same throughout an area. |
Correct Answer: B
Explanation:
The Process ID for OSPF on a router is only locally significant and you can use the same number on each router, or each router can have a different number-it just doesn’t matter. The numbers you can use are from 1 to 65,535. Don’t get this confused with area numbers, which can be from 0 to 4.2 billion.
QUESTION 123
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 |
Correct Answer: BCD
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.
QUESTION 124
Which one of the following IP addresses is the last valid host in the subnet using mask 255.255.255.224?
A. |
192.168.2.63 |
B. |
192.168.2.62 |
C. |
192.168.2.61 |
D. |
192.168.2.60 |
E. |
192.168.2.32 |
Correct Answer: B
Explanation:
With the 224 there are 8 networks with increments of 32 One of these is 32 33 62 63 where 63 is broadcast so 62 is last valid host out of given choices.
QUESTION 125
What command sequence will configure a router to run OSPF and add network 10.1.1.0 /24 to area 0?
A. |
router ospf area 0 network 10.1.1.0 255.255.255.0 area 0 |
B. |
router ospf network 10.1.1.0 0.0.0.255 |
C. |
router ospf 1 network 10.1.1.0 0.0.0.255 area 0 |
D. |
router ospf area 0 network 10.1.1.0 0.0.0.255 area 0 |
E. |
router ospf network 10.1.1.0 255.255.255.0 area 0 |
F. |
router ospf 1 network 10.1.1.0 0.0.0.255 |
Correct Answer: C
Explanation:
Enabling OSPFSUMMARY STEPS
1. enable
2. configure terminal
3. router ospf process-id
4. network ip-address wildcard-mask area area-id
5. end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Device> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configure terminal
Example:
Device# configure terminal
Enters global configuration mode.
Step 3
router ospf process-id
Example:
Device(config)# router ospf 109
Enables OSPF routing and enters router configuration mode.
Step 4
network ip-address wildcard-mask area area-id
Example:
Device(config-router)# network 192.168.129.16 0.0.0.3 area 0
Defines an interface on which OSPF runs and defines the area ID for that interface.
Step 5
end
Example:
Device(config-router)# end
Exits router configuration mode and returns to privileged EXEC mode.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/12-4t/iro-12-4t-book/iro-cfg.html#GUID-588D1301-F63C-4DAC-BF1C-C3735EB13673
QUESTION 126
On a live network, which commands will verify the operational status of router interfaces? (Choose two.)
A. |
Router# show interfaces |
B. |
Router# show ip protocols |
C. |
Router# debug interface |
D. |
Router# show ip interface brief |
E. |
Router# show start |
Correct Answer: AD
Explanation:
Only two commands “show interfaces” and “show ip interface brief” reveal the status of router interfaces (up/up, for example).
QUESTION 127
Refer to the exhibit. The two routers have had their startup configurations cleared and have been restarted. At a minimum, what must the administrator do to enable CDP to exchange information between R1 and R2?
A. |
Configure the router with the cdp enable command. |
B. |
Enter no shutdown commands on the R1 and R2 fa0/1 interfaces. |
C. |
Configure IP addressing and no shutdown commands on both the R1 and R2 fa0/1 interfaces. |
D. |
Configure IP addressing and no shutdown commands on either of the R1 or R2 fa0/1 interfaces. |
Correct Answer: B
Explanation:
If the no shut down commands are not entered, then CDP can exchange information between the two routers. By default, all Cisco device interfaces and ports are shut down and need to be manually enabled.
QUESTION 128
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 |
Correct Answer: BE
Explanation:
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.
QUESTION 129
Which command is used to display the collection of OSPF link states?
A. |
show ip ospf link-state |
B. |
show ip ospf lsa database |
C. |
show ip ospf neighbors |
D. |
show ip ospf database |
Correct Answer: D
Explanation:
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)
Link ID ADV Router Age Seq# Checksum Link count
2.2.2.2 2.2.2.2 793 0x80000003 0x004F85 2
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
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
10.1.1.1 111.111.111.111 794 0x80000001 0x001E8B
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 130
OSPF routing uses the concept of areas. What are the characteristics of OSPF areas? (Choose Three.)
A. |
Each OSPF area requires a loopback interface to be configured. |
B. |
Areas may be assigned any number from 0 to 65535. |
C. |
Area 0 is called the backbone area. |
D. |
Hierarchical OSPF networks do not require multiple areas. |
E. |
Multiple OSPF areas must connect to area 0. |
F. |
Single area OSPF networks must be configured in area 1. |
Correct Answer: BCE
Explanation:
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