Unit 2 Data Communications
While designing your network's VLAN topology, your team has decided to use a centrally managed DHCP server rather than creating a separate DHCP server for each VLAN. What software will you need to make the central DHCP server accessible across VLANs? Hypervisor DHCP relay agent Virtual router DHCP server
DHCP relay agent
What area of a network can provide less stringent security so a web server is more accessible from the open Internet?
DMZ (Demilitarized zone)
What is the difference between dynamic ARP table entries and static ARP table entries?
Dynamic ARP entries are created when a client makes an ARP request for information that isn't on the current ARP table. Static ARP tables are entered manually using the ARP utility. Which two fields in an
What type of fiber cable problem is caused when pairing a 50-micron core cable with a 62.5-micron core cable?
Fiber type mismatch
Which two protocols manage neighbor discovery processes on IPv4 networks?
ICMP and ARP
How many bits of a Class A IP address are used for host information?
24
Which formulas can be used to calculate the magic number? Choose two. 256 - the interesting octet 2h - 2 2n 2h
256 - the interesting octet 2h
Subnetting operates at Layer ____ while VLANs function at Layer ____
3, 2
Suppose your organization uses the Class B network ID of 172.20.0.0 for its entire network and wants to create 15 subnets. You first need to decide how many bits to borrow from the host address bits. Recall that you can use the formula 2n = Y. For the new subnets, how many bits must be borrowed from the host address portion?
4
What is the least number of bits you would need to borrow from the network portion of a Class B subnet mask to get at least 130 hosts per subnet?
8
Which IEEE standard determines how VLANs work on a network?
802.1Q
Which IEEE standard determines how VLANs work on a network? 802.11 802.1Q 802.3af 802.1x
802.1Q
When connecting a trunk link between two switches, it is important to configure the allowed VLANs correctly on either end. If this is not done correctly, which of the following can occur? A bottleneck A VLAN mismatch Incorrect pin-out A duplex mismatch Transceiver mismatch
A VLAN mismatch
What kind of cable uses BNC connectors? Which connector is likely to be used by cable TV?
Coaxial cable, F-connector
What three characteristics about TCP distinguish it from UDP?
Connection-oriented Sequencing and checksums Flow control
What characteristic of optical transmissions is primarily responsible for the distance limitations of fiber-optic cabling?
Cost and Optical loss
An attacker configures a VLAN frame with two tags instead of just one. The first tag directs the frame to the authorized VLAN. After the frame enters the first VLAN, the switch appropriately removes the tag, then discovers the next tag, and sends the frame along to a protected VLAN, which the attacker is not authorized to access. What kind of attack is this?
VLAN hopping
Suppose you're creating patch cables to be used in a government office. What color wire goes in the first pin?
White/green
Which transmission characteristic is never fully achieved?
bandwidth
What kind of tool can measure the distance to the location of damage in a cable?
cable performance tester
When a router can't determine a path to a message's destination, where does it send the message?
default router
What database does a router consult before determining the most efficient path for delivering a message?
routing table
Which Linux utility provides output similar to Wireshark's?
tcpdump
What process is used to establish a TCP connection?
three-way handshake
Which port mode on a switch enables that port to manage traffic for multiple VLANs? Ethernet Console Trunk Access
trunk
What fiber is used in fiber-optic cabling to protect the inner core and prevent the cable from stretching?
Kevlar
At which OSI layer does IP operate?
Layer 3 - Network Layer
What is the difference between short circuits and open circuits?
Short circuit is an unwanted connection, ie. Exposed wires touching. Open circuit is one where needed connections are missing, ie. Wire breaks
Why is SMF more efficient over long distances than MMF?
Signals traveling over MMF experience greater attenuation than those on SMF
What kind of route is created when a network administrator configures a router to use a specific path between nodes?
Static Route
Which protocol's header would a Layer 4 device read and process?
TCP
How is latency measured, and in what unit?
The delay from when the data leave the source and when it arrives, the unit is called RTT (round trip time)
Why do APC ferrules create less back reflection than UPC ferrules?
The end faces are placed at an angle to each other
Which hexadecimal block in an IPv6 address is used for the Subnet ID? The first one The fourth one The third one The eighth one
The fourth one
What is a twist ratio, and why is it important?
The number of twist per meter is know as twist ratio. The more twist per meter, the more it is resistant to cross talk.
Which of the following is not a good reason to segment a network? To narrow down the location of problems on a network To increase the number of networking devices on a network To reduce the demand on bandwidth To limit access to broadcast domains
To increase the number of networking devices on a network
Which part of a toner and probe kit emits an audible tone when it detects electrical activity on a wire pair?
Tone locator
What is the network ID with CIDR notation for the IP address 172.16.32.108 whose subnet mask is 255.255.255.0?
/24
What is the Internet standard MTU?
1,500 bytes
Suppose your organization uses the Class B network ID of 172.20.0.0 for its entire network and wants to create 15 subnets. You first need to decide how many bits to borrow from the host address bits. Recall that you can use the formula 2n = Y. How many bits total will be used for identifying a host's subnet?
16
A routing protocol's reliability and priority are rated by what measurement?
AD
Which routing protocol does an exterior router use to collect data to build its routing tables? OSPF IP RIPv2 BGP
BGP (Border Gateway Protocol)
Which of these categories of twisted-pair cable can support Gigabit Ethernet?
Cat 5e, Cat 6a, Cat 7
What is the earliest twisted-pair cabling standard that meets the minimum requirements for 10GBase-T transmissions?
Cat 6
What field in a TCP segment is used to determine if an arriving data unit exactly matches the data unit sent by the source?
Checksum
Which fiber connector contains two strands of fiber in each ferrule?
MTRJ
Which VLAN is designed to support administrative access to networking devices?
Management VLAN
Which protocol is supported by ICMPv6 to facilitate neighbor discovery on an IPv6 network?
NDP (Neighbor Discovery Protocol)
Which kind of crosstalk occurs between wire pairs near the source of the signal?
NEXT
Which VLAN on a switch manages untagged frames?
Native VLANs
Enter the Name of the OSI Layer #3
Network Layer
Which OSI layer is responsible for directing data from one LAN to another?
Network Layer
What do well-chosen subnets accomplish? Routing efficiency is decreased by ensuring IP address spaces are not mathematically related. IP address spaces overlap for easier management. Network documentation is easier to manage. Problems affect the entire network, making them more difficult to pin down.
Network documentation is easier to manage
Which two fields in an Ethernet frame help synchronize device communications but are not counted toward the frame's size?
Preamble and SFD (start frame delimiter)
Pick three IGPs (interior gateway protocols).
RIP, RIPv2, EIGRP, OSPF
What three routing metrics used by routers to determine the best of various available routing paths.
Routing metrics may be calculated using any of several variables, including hop count, bandwidth, delay, MTU, cost, and reliability.
Which fiber transceiver is the same size as SFP transceivers, but can support network speeds over 10 Gbps?
SPF+