An Expert interview about 100 105 icnd1
Q121. - (Topic 7)
What is the default lease time for a DHCP binding?
A. 24 hours
B. 12 hours
C. 48 hours
D. 36 hours
Explanation: By default, each IP address assigned by a DHCP Server comes with a one-day lease, which is the amount of time that the address is valid. To change the lease value for an IP address, use the following command in DHCP pool configuration mode:
Q122. - (Topic 1)
Refer to the exhibit.
If host A sends an IP packet to host B, what will the source physical address be in the frame when it reaches host B?
When packets transfer from one host to another across a routed segment, the source IP address always remains the same source IP address, and the source physical (MAC) address will be the existing router’s interface address. Similarly, the destination IP address always remains the same and the destination physical (MAC) address is the destination router’s interface address.
Q123. - (Topic 1)
Which layer of the OSI model controls the reliability of communications between network devices using flow control, sequencing and acknowledgments?
Q124. - (Topic 3)
What information can be used by a router running a link-state protocol to build and maintain its topological database? (Choose two.)
A. hello packets
B. SAP messages sent by other routers
C. LSAs from other routers
D. beacons received on point-to-point links
E. routing tables received from other link-state routers
F. TTL packets from designated routers
Reference 1: http://www.ciscopress.com/articles/article.asp?p=24090&seqNum=4
Link state protocols, sometimes called shortest path first or distributed database protocols, are built around a well-known algorithm from graph theory, E. W. Dijkstra'a shortest path algorithm. Examples of link state routing protocols are: Open Shortest Path First (OSPF) for IP The ISO's Intermediate System to Intermediate System (IS-IS) for CLNS and IP DEC's DNA Phase V Novell's NetWare Link Services Protocol (NLSP) Although link state protocols are rightly considered more complex than distance vector protocols, the basic functionality is not complex at all:
Each router establishes a relationship—an adjacency—with each of its neighbors.
Each router sends link state advertisements (LSAs), some
Each router stores a copy of all the LSAs it has seen in a database. If all works well, the databases in all routers should be identical.
The completed topological database, also called the link state database, describes a graph of the internetwork. Using the Dijkstra algorithm, each router calculates the shortest path to each network and enters this information into the route table. OSPF Tutorial
Q125. - (Topic 7)
Which feature allows a device to use a switch port that is configured for half-duplex to access the network?
C. port security
D. split horizon
Ethernet began as a local area network technology that provided a half-duplex shared channel for stations connected to coaxial cable segments linked with signal repeaters. In this appendix, we take a detailed look at the half-duplex shared-channel mode of operation, and at the CSMA/CD mechanism that makes it work. In the original half-duplex mode, the CSMA/CD protocol allows a set of stations to compete for access to a shared Ethernet channel in a fair and equitable manner. The protocol’s rules determine the behavior of Ethernet stations, including when they are allowed to transmit a frame onto a shared Ethernet channel, and what to do when a collision occurs. Today, virtually all devices are connected to Ethernet switch ports over full-duplex media, such as twisted-pair cables. On this type of connection, assuming that both devices can support the full-duplex mode of operation and that Auto-Negotiation (AN) is enabled, the AN protocol will automatically select the highest-performance mode of operation supported by the devices at each end of the link. That will result in full-duplex mode for the vast majority of Ethernet connections with modern interfaces that support full duplex and AN.
Q126. - (Topic 1)
Refer to the exhibit.
The exhibit is showing the topology and the MAC address table. Host A sends a data frame to host D. What will the switch do when it receives the frame from host A?
A. The switch will add the source address and port to the MAC address table and forward the frame to host D.
B. The switch will discard the frame and send an error message back to host A.
C. The switch will flood the frame out of all ports except for port Fa0/3.
D. The switch will add the destination address of the frame to the MAC address table and forward the frame to host D.
When switch receives the data frame from the host not having the MAC address already on the MAC table, it will add the MAC address to source port on MAC address table and sends the data frame.
Q127. - (Topic 1)
Which network device functions only at Layer 1 of the OSI model? A. Option A
B. Option B
C. Option C
D. Option D
E. Option E
Most hubs are amplifying the electrical signal; therefore, they are really repeaters with several ports. Hubs and repeaters are Layer 1 (physical layer) devices.
Q128. - (Topic 3)
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
Enabling OSPFSUMMARY STEPS
router ospf process-id
network ip-address wildcard-mask area area-id
Command or Action Purpose Step.1 enable
Device> enable Enables privileged EXEC mode. . Enter your password if prompted.
Step.2 configure terminal
Device# configure terminal Enters global configuration mode.
Step.3 router ospf process-id
Device(config)# router ospf 109
Enables OSPF routing and enters router configuration mode.
Step.4 network ip-address wildcard-mask area area-id
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.
Exits router configuration mode and returns to privileged EXEC mode.
Q129. - (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.
To form an adjacency (become neighbor), router A & B must have the same Hello interval, Dead interval and AREA numbers
Q130. - (Topic 7)
Which routing protocol has the smallest default administrative distance?
Explanation: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/15986-admin-distance.html Default Distance Value TableThis table lists the administrative distance default values of the protocols that Cisco supports:
Route Source Default Distance Values
Connected interface 0 Static route 1 Enhanced Interior Gateway Routing Protocol (EIGRP) summary route 5 External Border Gateway Protocol (BGP) 20 Internal EIGRP 90 IGRP 100 OSPF 110 Intermediate System-to-Intermediate System (IS-IS) 115 Routing Information Protocol (RIP) 120 Exterior Gateway Protocol (EGP) 140 On Demand Routing (ODR) 160 External EIGRP 170 Internal BGP 200 Unknown*