Module 14 - Networking Flashcards
1
Q
What is a LAN?
A
Local Area Network: A computer network that covers only a small area, usually within one building.
2
Q
What is a WLAN?
A
Wireless Local Area Network: A Type of LAN that does not use wires or cables to create connections, but instead transmits data over radio or infrared waves.
3
Q
What is a WAN?
A
Wide Area Network: A network or group of networks that span a large geographical area.
4
Q
What is a MAN?
A
Metropolitan Area Network: A network that covers a large campus or city. A small MAN is sometimes called a Campus Area Network (CAN).
5
Q
What is a PAN?
A
A Personal Area Network: A Network centered around one individual, consisting of personal devices at close range typically within a few meters.
- Wireless PAN uses technologies such as Bluetooth and Infrared (IrDA)
6
Q
What is a SOHO?
A
Small Office / Home Office: Refers to a small business or business-at-home.
7
Q
What is a WAP?
A
Wireless Access Point: A device that allows wireless communication devices to connect to a wireless network using Wi-Fi, bluetooth, or related.
- WAP usually connets to a router and can relay data between the wireless devices and wired devices on the network.
8
Q
What is a VPN?
A
Virtual Private Network: Uses a public network, such as the internet, to carry encrypted traffic between two points, such as between two remote offices.
- VPN is typically used to provide remote offices or individual users with secure access to their organization’s network.
- VPN can be contrasted wtih an expensive system of owned or leased lines.
- VPN provides the same capabilities at a much lower cost.
9
Q
What is a NIC?
A
- Network Interface Card
- Connects the networking device to the media
- Converts signal used on the media to the type used by the networking device and vice-versa.
10
Q
What is the difference between link lights and activity lights?
A
- Link light remains steady to indicate connectivity.
- Activity light blinks to indicate activity (network traffic passing through the NIC)
11
Q
What is a MAC?
A
Media Access Control (MAC) Address:
- Unique address burned-in to the card by the manufacturer, sometimes called the hardware address or physical address.
- Address is 48 bits long, or 6 pairs of Hex digits.
12
Q
What do the first three Hex pairs of a MAC Address represent?
A
The vendor
- The last three hex pairs represent the ID for the card itself.
13
Q
What is an uplink port?
A
The connection between switches, when switches are combined to make a larger network.
14
Q
How can you find the MAC address?
A
Revealed with the command ipconfig/all
15
Q
What is a Repeater?
A
- Allow a cabling system to extend beyond its maximum allowed length by amplifying the network voltages so signals travel farther.
16
Q
What is a Hub?
A
- A Data Concentrator
- A broadcast-based device (1 to many), when one host transmits, all hosts connected recieve.
- Inefficient and allow many collisions on the network.
- Link lights i ndicate connectivity and activity lights indicate traffic passing through.
- All activity lights light up whenever a host starts to transmit.
17
Q
What is a Switch?
A
- A Data concentrator like a hub
- Unlike hub, it is unicast-based (1 to 1).
- One host transmits, only the destination host receives.
- Eliminates ethernet collisions
- Provides full duplexing, meaning two hosts can send and receive at the same time.
- A switch will light the 2 LED’s for the ports of two communicating hosts.
18
Q
What type of port does a hub and switch both have?
A
Several RJ45 ports, typically in multiples of 4.
19
Q
What is a proxy server?
A
- Sits between an organizations’s LAN and the internet
- “listens” for internet traffic, caches what is idnetified so that other requests to the same place could come from cache, thus speeding things up.
- Can also block traffic to the internet to to specific sites.
- Can provide caching, filtering, and monitoring of network traffic.
20
Q
What is a Router?
A
A device that connects two different networks.
- Connects the LAN to the internet or to other internal/external networks
- Has at least 2 ports, one on the LAN side and one on the network side (often called WAN side)
21
Q
What is a Gateway?
A
- A router that interconnects two netwroks that use two different network protocols.
- Could connect a TCP/IP to a IPX/SPX.
- A gateway can translate between hots on two networks.
22
Q
What are routing protocols?
A
- Specifies how routers communicate with one another
- Can use several Network transmission methods on a single device to communicate with other routers.
23
Q
T/F - Many routers allow you to connect to a configuration page via a browser and an IP address
A
True
24
Q
What is a firewall?
A
A device and/or software that analyzes incoming/outgoing data packets and makes an allow or deny decision.
- Can look into the data packet and make decisions based on:
- Port number (80 = http, 25 = SMTP, etc)
- Source or destination IP address
- Type of protocol (TCP, UDP, etc)
25
What is NAS?
Network Attached Storage
* Device used to store data on a network
* Convenient method of sharing files among multiple computers on a network
* Benefits over file serves include faster data access and easier configuration.
26
What is VOIP?
Voice Over Internet Protocol
* Allows voice to be sent over data lines
* Benefits from Quality of Service (QoS), which assigns higher priorities to voice traffic.
* Phones use an RJ-45 connection
* Power over Ethernet (PoE) is used to provide power to VoIP phones
27
What is the DMZ?
Demilitarized Zone
* Provides a buffer zone that separates an internal network from the internet
* Firewalls separate internet from DMZ, and the DMZ from the internal network
* Types of serves typically placed in DMZ's include:
* web servers
* front-end email servers
* gaming servers
28
What is the max cable length for 802.3 ethernet?
1. 33 feet (10 meters)
2. 100 feet (30 meters)
3. 328 feet (100 meters)
4. 1200 feet (366 meters)
3. 328 feet (100 meters)
29
What is Peer-to-Peer networking model?
* Computers act as both clients and servers
* Difficult to administer - highly decentralized
* Works with 10 or less computers
* Called a Workgroup in Windows
30
What is the Client-Server Networking Model?
* Centralized server functions as repository for files and resources.
* Easy to administer
* Works well in large networks (10 + computers)
31
What is a Domain Controller?
* In Windows Domain network, a Domain Controller is a server used to store domain useraccounts that users can login with.
32
What are cached credentials?
* When a users logs into a domain, the user's computer caches locally the domain account information.
* This allows the user to log into the domain even if they can't connect to the Domain Controller server.
33
Which of the following will allow a user account to logon to Windows Vista when a Windows domain name needs to be specified (Select TWO):
1. domain\username
2. username@domain
3. username-domain
4. domain-username
5. domain username
1. domain\username
2. username@domain
34
What does physical topology refer to?
The layout of cable that connects computers and other devices together.
35
What does Logical Topology refer to?
How data moves among network hosts.
36
What is Bus Topology?
* All nodes connect on a single coaxial cable
* Each end of network must be terminated
* Faulty terminators, connectors, or cables can disable part or whole network
37
What is Star Topology?
* All nodes connect to a central point, typically a hub or switch
* Uses different cable types, including twisted pair, fiber optic, wireless
* Failure of cable affects just one node
* Failure of concentrator (hub or switch) downs the network
38
What is Ring Topology?
* Ring of cable, one end connected to another
* Signals travel around the ring
* Token Ring and Fiber Distributed Data Interface (FDDI) are two popular examples
* Typical speed is either 4 or 16 Mbps
* Concentrator is called a Multi-Station Access Unit (MAU)
39
What is Mesh Topology?
* Every node is connected to every other mode
* Advantage is redundancy, disadvantage is cost
* Not practical for LANs
* Primarily used in WAN's
40
Name Three Media Access Methods:
1. Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
2. Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)
3. Token Passing
41
Describe CSMA/CD:
* Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
* Computer first listens to the wire.
* If no traffic detected, computer transmits its data
* If another computer transmits at the same time, a collision occurs and no data can be transmitted for either machine.
* Part of the IEEE 802.3 standard
42
Describe CSMA/CA:
Computer Sense Multiple Access with Collision Avoidance (CSMA/CA):
* Computer first listens to wire, if no traffic detected the computer sends a signal that it is rady to transmit data.
* If the ready signal transmits without a problem, computer than transmits its data.
* Used in IEEE 802.11 wireless networks and in AppleTalk
* Slower and less popular than CSMA/CD
43
Describe Token Passing:
* Special packet of data, called a token is passed from co mputer to computer.
* Any computer that has data to transmit must wait for the token
* Part of IEEE 802.5 standard, also known as Token Ring network
44
What is Full Duplex?
Can carry data in both directions at the same time
45
What is half duplex?
Can carry data in both directions, but only one direction at a time.
* Network hubs can run in this mode by design.
46
List 5 Different Connectors for Coaxial Cable:
1. RG-8 (known as Thicknet 10base5) 15-pin AUT Attachment Unit Interface
2. RG-58 (known as Thinnet 10base2) or BNC T - British Naval Connector
3. RG-6 - used to carry audio/visual signals from devices such as cable boxes and satellite dishes to television displays. Used mainly with digital cable and satellite signals
4. RG-59 - used mainly for analog cable TV
5. F Connectors - typical coax connector seen in homes
47
Describe elements of Coaxial Cable:
* Single copper wire down the middle
* Braided shield around it
* Cable is stiff and difficult to work with
* Becoming increasingly rare in networks these days
48
What are the two types of Twisted Pair Cable:
1. UTP - Unshielded Twisted Pair - Least expensive and most popular for Local Area Networks
2. STP - Shielded Twisted Pair - metallic foil shielding around the pairs of wires protects from electromagnetic interference caused by electrical motors, transmitters, et. STP is more expensive, so it's only used when situation demands.
49
What connectors are used in Twisted Pair Cables?
1. RJ45 - for networking
2. RJ11 - for telephones and dial-up modems
50
How many wires in UTP/STP cables?
Eight wires (four twisted pairs).
51
How many wires in Plain Old Telephone Service (POTS)?
Four wires - POTS uses RJ11 connectors
52
What are the wires twisted in UTP/STP?
Reduces crosstalk and resistance to outside interference.
53
What are the seven grades of UTP Cable?
1. Cat 1 - Voice grade (VG), not for data
2. Cat 2 - VG and low speed data
3. Cat 3 - VG, 10 Mbps Ethernet, 4 Mbps Token Ring (most often found in POTS)
4. Cat 4 - 16 Mbps Token Ring
5. Cat 5 - 100 Mbps Ethernet (aka Fast Ethernet)
6. Cat 5e - 1000 Mbps Ethernet
7. Cat 6 - 1000 Mbps or higher Ethernet (thicker cable)
54
What is straight-through UTP cable used for?
* Used to connect two dissimilar devices to one another, such as a computer to a switch.
55
What is crossover UTP cable used for?
* Used to connect two similar devices to one another, such as computer direct to computer.
56
What are plenum rated cables?
* cables that do not give off toxic fumes when burned.
* Used inside plenums (spaces between floors of buildings)
* More expensive then PVC (polyvinyl chloride), but safer in the event of a fire
57
List five elements of Fiber Optic Cable:
1. Signals transmitted as pulses of light through glass or plastic
2. Immune to EMI (electromagnetic interference)
3. Signals can travel much farther than on copper
4. More expensive than copper
5. Needs special tools, is fragile and more difficult to work with.
58
What is singlemode fiber?
* One frequency, light source is a laser
* Used for long hauls, up to 24 miles/40km
* More expensive than multimode
* More fragile than multimode, cannot be bent as much as multimode
59
What is multimode Fiber?
* Multi wavelengths, light source is LED
* Travels shorter distances than singlemode (up to 3000 feet)
* Cheaper and less fragile than singlemode
60
List Four Types of Fiber Optic Connectors:
1. SC (Standard Connector)
2. ST (Straight Tip)
3. LC (Local Connector)
4. MT-RJ (Mechanical transfer RJ)
61
What is the transfer speed and max length of ThinNet Cable (10Base2)?
* 10 Mbps
* 185 meters
* Uses BNC connector
62
What is the transfer speed and max length of ThickNet cable (10Base5)?
* 10 Mbps
* 500 Meters
* Uses an AUI 15-pin D-shaped connector
63
What is the transfer speed and max length of 10BaseT (Twisted Pair) Cable?
* 10 Mbps
* **100 meters** (328 feet)
* Uses an RJ-45 connector
* 100 BaseT = 100 Mbps
* Gigabit Ethernet = 1 Gbps
* 10-Gigabit Ethernet = 10 Gbps
* "T" denotes Twisted Pair
64
What is the transfer speed and max length of 10BaseF Cable?
* 10 Mbps
* **Up to 2 kilometers**
* Uses ST or SC connectors, or LC and MT-RJ connectors
* 100BaseFL = 100 Mbps
* 1000BaseFX = 1 Gbps
* 1000BaseX = 10 Gbps
65
T/F - When transferrring data between two network devices with different transfer speeds, data is transferred at speed of slower device.
* True.
* Example - If you connect a 10/100 NIC to a 10/100/1000 switch, the maximum transfer rate is 100 Mpbs
66
What is a Cable Tester used for?
* Test the integrity of the cable (ie. the ability for the cable to carry an electrical signal)
* Testers are available for twisted pair, fiber optic, and coaxial
* For twisted pair, can determine if cable is straight-through or crossover.
67
What is an Induction Toner (aka Toner Probe) used for?
* Can be used to trace a cable that begins in one area, such as a user's work space, to another area such as a wiring closet.
* Consists fo two units, one puts the tone on the wire and the other is a proble that locates the cable with the tone on it. (sometimes referred to as the "fox and hound")
68
What is a Loopback Plug used for?
* A connector for diagnosing transmission problems
* For testing the port/interface inside the computer or device.
* Could use to troubleshoot a NIC that is not receiving an IP address
* Plugs into a port, such as a serial or parallel port, and crosses over the transmit line to the receive line so that outgoing signals can be redirected back into computer.
69
What is a Time Domain Reflectometer (TDR) used for?
* To detect faults in metallic cables
* Sends pulse down line and listens for reflected pulse from a break or short
* Uses time to estimate the distance where the fault lies
* Optical Time Domain Reflectometer (OTDR) is used to locate faults in fiber optic cables.
70
What is a Crimper Tool used for?
* To fasten a connector to the cabling of a twisted pair cable.
* Sometimes called "terminating a UTP cable"
71
What is a Punch Down Tool used for?
* Used to make sure network wires are securly fastened in a wall jack
* Used to insert network wires into RJ-45 jacks and patch panels
* Most are impact type which push the wire into the slot, cuts the insulation, and secures the wire.
72
What are the differences in the T568A vs T568B Wiring Standards for Twisted Pair Cable?
* T568A - Starts with two green wires in 1 & 2 positions
* T568B - Starts with two orange wires in 1 & 2 positions
* All other wires in same spots (blue pair in 4&5, brown pair in 7&8)
73
Place the following cable types into increasing max distance:
* Coax
* UTP (CAT)
* Fiber
1. CAT (Max 328 ft / 100 meters)
2. Coax (Max 550 ft)
3. Fiber (Max 25 miles)
74
Which of the following cable types uses a BNC?
1. Fiber
2. CAT6
3. Coaxial
4. UTP
* Coaxial
75
What are the seven layers in Open System Interconnection (OSI) Networking Model?
1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer
5. Session Layer
6. Presentation Layer
7. Application Layer
76
What is in the Physical Layer of OSI (Layer 1)?
* Hubs, Repeaters, Network Adapters Exist Here
* Defines the elctrical and mechanical characteristics used to access bits over a physical medium (including, pins, voltages, and cable specs)
77
What is in the Data Link Layer (Layer 2) in OSI?
* Switches, Bridges, MAC Addresses operate at this layer
* Ethernet (IEEE 802.2)
* Bits from the physical layer are "framed" in the data link layer
* Responsible for reliable delivery at the lowest levels, including framing of data
78
What is in the Network Layer (Layer 3) of OSI?
* IP, IMCP, and ARP operate at this level
* Routers operate at this layer
* Provides network addressing and routing of data
79
What is in the Transport Layer (Layer 4) of OSI?
* TCP Transmission Control Protocol (connection-oriented, guaranteed deliver)
* UDP User Datagram Protocl (connectionless, faster, delivery not guaranteed)
* Provides error detection, correction, and end-to-end communications between devices
80
What is in the Session Layer (Layer 5) of OSL?
* Controls dialogs/connections (sessions) between computers
* Establishes, manages, and terminates sessions between computers
* Provides for
* Full Duplex
* Half Duplex
* Simplex Communications
81
What is in the Presentation Layer (Layer 6) of OSL?
* Provides data transformation and conversion
* Data encryption, compression, EBCDIC to ASCII
82
What is in the Application Layer (Layer 7) of OSL?
* Provides network services for user applications
* HTTP
* FTP
* Email (SMPT, POP3, IMAP)
* SNMP, etc
83
What is Networking Protocol?
Identify four Networking Protocols:
The specifications defining procedures for transmitting and receiving data, such as data format, timing, sequence, and error-checking.
1. ARP - Address Resolution Protocol
2. ICMP - Internet Control Messaging Protocol
3. Internet Protocol IPv4
4. Internet Protocol IPv6
84
What does OSI stand for?
1. Open Source Inspection
2. Open Source Interconnection
3. Open System Interconnection
4. Optical Systemic Inspection
Open System Interconnection (OSI) Networking Model
85
What is ARP?
Address Resolution Protocol
* ARP results a known IP address to an unknown MAC (physical address).
* All communications between two hosts on the same LAN require that each host knows the other's MAC address before data transmission can beging.
* ARP-a command displays IP addresses resolved to associated MAC addresses. Values are memory resident and disappear when the host is shut down.
86
What is ICMP?
Internet Control Messaging Protocol
* Informs a source host about errors in packet processing
* Probe the network with request and reply messages to determine general network characteristics
* PING command uses ICMP
* Often restricted by network admins as it offers a way for malicious attacks on a network
87
How many bits long is an IPv4 address?
* 32 bits
* Represented as w.x.y.z, each of which is an octet
88
What is the purpose of IPv4?
Responsible for routing data from the source to the final destination.
Located in the Network Layer of the OSI model.
89
What is the Subnet Mask within IPv4?
* Each IP address has two parts, the network section and the host section.
* The subnet mask determines which part of the IP address is the network portion and which part is the host portion.
90
What are the three IP address classes in IPv4?
* Class A - Starts 1-127. 8 bits Network ID, 24 bits Host ID
* Class B - Starts 128-191. 16 bits Network ID, 16 bits Host ID
* Class C - Starts 192-223. 24 bits Network ID, 8 bits Hosts ID
91
What is multicasting?
* When one network device sends data to a set or group of devices using an IP address in the Class D Range (224-239).
* In contrast, unicast communications occur when one network device sends data to one recipient device (as in a switch).
92
What is a Loopback Address?
* An IPv4 address that begins with 127.
* An IPv6 address that is 0:0:0:0:0:0:0:7, or ::1
* The commands PING 127.0.0.1 and PING Localhost do not generate any network traffic, and simply test that TCP/IP is installed correctly on a computer.
93
What is an APIPA?
Automatic Private IP Address
* An IP address in the range of 169.254.0.1 - 169.254.255.254
* In the event that a Windows computer is to receive an IP address from a DHCP server, but the server is unavailable, Windows will assign itself an IP address in the 169 range.
94
What is a Broadcast Address?
An IP address of 255.255.255.255
* Occurs when a computer needs to contact another computer on a network but does not know the target computer's IP address.
* Sends the message to ALL computers using the broadast address.
95
What is a Public IP Address?
Addresses that are accessible from the internet.
* When a company applies for a Class A, B, or C address, it is assigned a public address that is different from all other public IP addresses.
96
What is a Private IP Address?
Addresses that are not accessible from the internet.
97
Which of the following are valid private IP addresses (Select Three):
1. 10.0.0.0 through 10.255.255.255
2. 172.16.0.0 through 172.31.255.255
3. 172.1.0.0 through 172.15.255.255
4. 192.168.0.0 through 192.168.255.255
5. 192.1.0.0 through 192.167.255.255
* 1. 10.0.0.0 through 10.255.255.255
* 2. 172.16.0.0 through 172.31.255.255
* 4. 192.168.0.0 through 192.168.255.255
98
Name Three IPv4 Rules:
1. The largest number that can appear in any octet of an IP address is 255 decimal (which is equivalent to 8 binary one's).
2. A host on a network cannot be assigned an IP address that starts with 0, 127, or 255 in the first octet.
3. The entire Host ID portion of an IP address cannot be equal to all binary zeroes (0 decimal) or ones (255 decimal)
99
How many bits long is an IPv6 address?
128 bits
* Represented by 8 groups of 16-bit hexadecimal values separated by colons:
* **2001 : 0db8 : 85a3 : 0000 : 0000 : 8a2e : 0370 : 7334**
100
Is IPv6 supported by all routers?
* Not yet
* Can exist on the same network
* IPv6 does not implement interoperability with IPv4, modern OS's use dual-protocol for transparent access to either v4 or v6.
101
What are the abbreviation rules for IPv6?
1. Leading zeroes within a 16-bit value may be omitted.
2. One or more groups of consecutive zeroes within an address may be replaced by a double colon. A double colon can only appear once in an address.
102
What is slash notation in IPv4 addresses?
Indicates the number of leftmost bits representing the network ID.
* Class A = /8
* Class B = /16
* Class C = /24
103
What is NAT?
Network Address Translation
* The mapping of private IP addresses to a public IP address
* Prevents incoming (public) session initiation
104
What is TCP?
Transmission Control Protocol
* Provides reliable delivery of data between hosts on a network
* Connection-oriented, meaning that the communicating hosts on a network first establishes the connection between them.
105
What is UDP?
User Datagram Protocol:
* Provides unreliable delivery of data between hosts
* Connectionless, meaning that data can be transmitted without first establishing a connection between them.
106
Identify four Protocol Suites:
1. TCP/IP - Required to access the internet
2. IPX/SPX - Default for Novell Netware OS before Netware 5
3. Appletalk - Protocol and proprietary network architecture for Macs
4. NetBIOS - very simple and very fast protocol that requires little setup. Used by a Windows Networking protocol called NetBEUI, which cannot be routed and thus cannot be used on a WAN.
107
What is Port 20 used for?
Port 20:
* File Transfer Protocol (FTP) data channel
* Used for transmitting files between two computers
108
What is Port 21 used for?
Port 21:
* FTP control channel
* Used for exchanging commands and responses by FTP connected systems.
109
What is Port 22 used for?
Port 22:
* SFTP (Secure File Transfer Protocol)
* SSH (Secure Shell), a client/server application used primarily on Linux/Unix based systems to access shell accounts on an SSH server.
110
What is Port 25 used for?
Port 25:
* SMTP (Simple Mail Transfer Protocol) used to **send** email messages
111
What is Port 53 used for?
Port 53:
* Domain Name System, resolves friendly host/domain names to IP addresses.
112
What is Port 80 used for?
Port 80
* HTTP (Hypertext Transfer Protocol)
* Used by web servers to receive requests from client browsers.
113
What is Port 110 used for?
Port 110:
* POP3 - Post Office Protocol 3, used to **receive** email requests from clients.
114
What is Port 143 used for?
Port 143:
* IMAP4 (Internet Message Access Protocol)
* Used to receive email requests from clients.
* Allows mailboxes to be synchronized, so that changes from one device will be reflected on the other.
115
What is Port 119 used for?
Port 119
* NNTP Network News Transfer Protocol, used to host newsgroups
116
What is Port 161 used for?
Port 161
* SNMP - Simple Network Management Protocol
* Used to monitor network-attached devices (computers, switches) for conditions that warrant administrative attention
* Can also be used to configure the status and features of network devices.
117
What is Port 443 used for?
Port 443:
* HTTPS (Hypertext Transfer Protocol Secure)
* A combination of HTTP with Secure Sockets Layer (SSL) to make for a secure connection
118
What is Port 3389 used for?
Port 3389:
* Remote Desktop Protocol
* Allows access to a remote computer's desktop
119
What is Port 8080 used for?
Port 8080:
* HTTP - Alternate
* This port is a popular alternative to port 80 for offering web services.
* 8080 was chosen since it is two 80's and
120
What is DHCP?
Dynamic Host Configuration Protocol
* Automatically assigns IP addresses to hosts on a network
121
What is a static IP address assignment?
When a user manually types in an IP address.
122
What is scope and exclusion scope in DHCP?
Scope = a specific range of IP addresses which a DHCP server can assign to hosts on a network.
Exclusion Scope = Specifies addresses within the scope which should not be given out by the DHCP server.
123
What is DNS?
Domain Name Service
* Resolves friendly host names to IP addresses
* Preferred DNS server - server your computer will always use
* Alternate DNS server - will use if Preferred is unavailable.
124
What is WINS?
Windows Internet Naming Service
* Resolves NetBIOS names to IP addresses on Microsoft networks.
125
Identify Six IPCONFIG commands and uses:
1. IPCONFIG - Displays a computer's IP address configuration
2. IPCONFIG / ALL - In addition to IP address, displays MAC (physical address), information about lease duration, IP addresses of DNS & WINS servers
3. IPCONFIG / Release - Causes a client to contact a DHCP server and release its current IP address
4. IPCONFIG / Renew - Causes a client to contact a DHCP server to renew its IP address
5. IPCONFIG / displaydns - Displays the contents of a computer's DNS cache.
6. IPCONFIG / flushdns - Deletes any items currently stored in a computer's DNS cache.
126
What is the PING command used for?
Tests connectivity on a network by sending a series of packets to another computer, which in return sends back a response.
* -a parameter tests for name resolution
* -t parameter causes pinging to continue until interrupted
* -l parameter changes the size of the data packet
* 127 - tests the loopback address to determine if TCP/IP is installed
* www.mywebsite.com - uses host name to find IP address of a remote computer
127
What is the NSLOOKUP command used for?
Name Server Lookup
* Allows you to verify entries on a DNS server.
128
What is the TRACERT command used for?
Displays the IP address of each router between the client and a target.
129
What is the PATHPING command used for?
A route tracing command that combines the features of Ping and Tracert with additional information that neither of those commands provide.
130
What is the NETSTAT command used for?
Displays protocol statistics and current TCP/IP network connections. Also shows which ports are active, listening or not connected.
131
What is the NBTSTAT command used for?
Displays protocol statistics and current TCP/IP connections using NBT (NetBIOS over TCP/IP)
132
What is the NETVIEW command used for?
Displays a list of shared resources on a specified host or workgroup/domain.
133
What is the NETUSE command used for?
Maps a drive letter to a shared folder on a network or displays a list of current network connections.
134
What is the GETMAC command used for?
Displays MAC addresses for all network adapters in a computer.
135
What are the classes of Bluetooth?
* Class 1 = 100 meter range
* Class 2 = 10 meter range (most popular)
* Class 3 = 5 meter range (least popular)
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What is Bluetooth?
* Standard for short-range wireless communication between devices such as cell phones, PDA's, wireless headsets, mice, keyboards, etc.
* Commonly used to create a Personal Area Network (PAN).
* Enables devices to communicate wirelessly through short-range, ad-hoc networks known as **piconets.**
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What is the max number of devices in a piconet?
7 devices
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What is the data transfer speed of Bluetooth?
3 Mbps
139
What is the radio spectrum used for Bluetooth?
2.4 GHz frequency range
140
What happens in discoverable mode in bluetooth?
The device transmits information about itself, such as the device name, device class, and list of services it provides.
141
What occurs during Bluetooth pairing?
* Two bluetooth devices agree to communicate with each other and establish a connection.
* In order to pair two Bluetooth devices, a passcode has to be exchanged.
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What is the maximum range and data transfer speed for Infrared?
* 1 meter max range
* 16 Mbps
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What is IrDA?
Infrared
* Short-range, point-to-point wireless communication
* Requires line-of-sight between devices
* Being replaced by bluetooth technology
* Security is not an issue given the max range and the signal does not go through walls
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What is the frequency and throughput of 802.11a?
* Frequency: 5 GHz
* Throughput: 54 Mbps
* No longer widely used.
* NOT compatible with 802.11b/g because of frequency difference.
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What is the frequency, throughput, and range of 802.11b?
* Frequency: 2.4 GHz
* Throughput: 11 Mbps
* Range: 100 meters
* Can be interfered with by other devices that operate at 2.4 GHz, such as cordless phones, microwaves ovens, and Bluetooth devices
146
What is the frequency, throughput, and range of 802.11g?
* Frequency: 2.4 GHz
* Throughput: 54 Mbps
* Range: 100 meters
* Can be interfered with by other devices that operate at 2.4 GHz, such as cordless phones, microwaves ovens, and Bluetooth devices
147
What is the frequency, throughput, and range of 802.11n?
* Frequency: 2.4 GHz & 5GHz
* Throughput: up to 600 Mbps
* Range: Typcially greater than 802.11 b/g
* multiple input / multiple ouput (MIMO) allows two or more antennas to be used at both ends of transmission.
* Backwards compatible with 802.11 a/b/g
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What is Mixed Mode in Wifi?
* Wireless routers can be configured to broadcast in mixed mode because there is a mixture of 802.11 a/b/g/n network devices.
* Resulting speed is th slowest speed, for example when communicating between g and n devices, the resulting speed is 54 Mbps.
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What is ad-hoc mode?
* Two wireless computers communicate directly with one another.
* Does not require a Wireless Access Point (WAP)
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What is Infrastructure Mode?
* Computers connect to one anothe rvia a common Wireless Access Point (WAP)
* All wirelss clients must be configured to use the same SSID (Service Set Identifier),the name given to the wireless network.
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What is Disable SSID broadcasting?
* The WAP stops broadcasting its name so that anyone with a wireless computer can see it.
* Forces the user that wants to connect to type the name of the SSID.
152
What is MAC filtering?
* Allows the user to specify the MAC addresses able to use the access point.
* Essentially creates an Access Control List (ACL) of those allowed to connect to the wireless network.
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What are the three types of 802.11 encryption?
* WEP (Wired Equivalent Privacy) - Least secure
* WPA (Wi-FI Protected Access) - Stronger than WEP
* WPA 2 - stronger than WEP and WPA
