Module 1: Basics of Networking Flashcards
Review: - LAN, MAN, WAN,CAN, PAN - Internet, Subnet, intranets, extranets. - Wired topologies: logical vs physical, star, ring, mesh and bus. - The OSI model - Protocols and ports - Numbering systems (114 cards)
1
Q
What is a Network
A
A group of interconnected computers and other devices that able to share information with each other..
2
Q
What is a Node/Host
A
The individual devices connected to the network
3
Q
What is a Connected Media
A
The medium in which a host is connected to a network (example: cables or wifi).
4
Q
What is a Network Interface
A
Converts the digital data from a host to some form of signal (light, electric signals, radio, etc..) to travel from the host, to the network, then back to digital data that other hosts can interpret .
5
Q
What is a Network Protocol
A
Standards (like a key to a scrambled message) to define how data will be formatted. All computers must use the same protocol on the network or they will not be able to understand the data being communicated.
6
Q
What are some of the benefits of networks?
A
○ Reduce the need to buy multiple tools for every computer such as a printer or fax.
○ Consolidate storage into one place so each host can access the same information.
○ Data security since all the sensitive data is in one place.
○ Easier to back up one shared storage than each individual computer.
○ Reduce Telephone expenses.
○ Workflow management
7
Q
What is a peer to peer network?
A
Individual hosts don’t have a specific role. They provide and consume network services; function as a client and a server at the same time.
8
Q
What are some advantages of a peer to peer network?
A
- Easy to Implement
- No special software needed
- Inexpensive
9
Q
What are some disadvantages of a peer to peer network?
A
- Not scalable (The bigger it gets, the harder it is to manage).
- Difficult to support as there are no central controls.
- If a device(like a printer) is connected to computer, it is unreachable from other hosts if that computer is turned off.
- No centralized storage of data.
- increased security risk.
10
Q
What is a client-server network
A
A network where hosts have specific roles. Some hosts could act as servers while the others just act as clients. The server provides the resources, the clients use those resources.
11
Q
What are two types of networks?
A
- Peer-to-peer.
2. Client-server.
12
Q
What are advantages of client-server network
A
- Easily scalable
- Easier to support as it’s more centralized.
- Better security.
- Centralized storage.
13
Q
What are some disadvantages of a client-server network?
A
- Very expensive
- Requires lots of planning to figure which clients will be servers and where they will be placed.
14
Q
What is a subnet?
A
A part of a larger network where all of the computers share the same subnet address (much like houses share the same street address). Also referred to as a network address.
15
Q
What is a router?
A
A device that connects multiple subnets together to make a bigger network.
16
Q
What does LAN stand for?
A
Local Area Network
17
Q
What is a LAN?
A
A collection of connected subnets within the same organization.
18
Q
What does MAN stand for?
A
Metropolitan Area Network
19
Q
What is a MAN?
A
Many LAN’s connected in one area; A collection of interconnected networks within the same metropolitan area.
20
Q
What does WAN stand for?
A
Wide Area Network links
21
Q
What is a WAN?
A
A collection of MAN’s connected together.
22
Q
What is an Internetwork?
A
When two different networks, such as two LAN’s, use something like a WAN to connect to each other, but aren’t controlled by the same entity.
23
Q
What is the Internet?
A
A collection of many different networks owned by many different entities, that share information and communicate with one another.
24
Q
What does ISP stand for?
A
Internet Service Providers.
25
What does an ISP do?
Manage an access point to the internet.
26
What is an Intranet?
A private network available to those only within an organization.
27
What is an Extranet.
A private network that allows authorized external users, but not available to the public.
28
What does CAN stand for?
Campus Area Network
29
What is a CAN?
A computer network made up of an interconnection of local area networks (LANs) within a limited geographical area, such as a university's campus.
30
What does PAN stand for?
Personal Area Network
31
What is a PAN?
A very small network used for communicating between personal devices, such as Bluetooth.
32
What is Topology?
The term used to describe how devices are connected and how messages flow from device to device.
33
What does a Terminator do?
They absorb signals and prevent them from reflecting repeatedly back and forth on the cable. Terminators are used with bus topology.
34
What is a physical topology?
Describes the way the network is wired.
35
What is a logical topology?
Describes the way messages are sent.
36
Describe a Bus topology.
A bus topology consists of a trunk cable with nodes either inserted directly into the trunk or tapped into the trunk using offshoot cables called drop cables.
37
Describe a Ring topology.
A ring topology connects neighboring nodes until they form a ring. Signals travel in one direction around the ring; each device on the network acts as a repeater to send the signal to the next device.
38
Describe a Star topology.
A star topology uses a hub or switch to connect all network connections to a single physical location.
39
Which is the most popular type of topology used for a LAN?
Star
40
Describe a Mesh topology.
A mesh topology exists when there are multiple paths between any two nodes on a network. Mesh topologies are created using point-to-point connections. This increases the network's fault tolerance because alternate paths can be used when one path fails.
41
What are the two types of Mesh topologies?
Partial mesh: Some redundant paths exist.
| Full mesh: Every node has a point-to-point connection with every other node.
42
True or False: The logical topology is always the same as the physical.
False. A network can use one type of physical topology, while also use an entirely different logical topology.
43
How does a logical bus topology work?
The data is sent to ALL the computers. The computers then determine if the data is meant for them or not. If not, it discards it.
44
How does a logical ring topology work?
One computer sends data to the next computer until it reaches its destination.
45
How does a logical star topology work?
Data is sent to the central connecting device which then routes the data directly to the intended computer.
46
How does a logical mesh topology work?
Uses redundancy to create links between the computers. This is far more practical when using wireless communication as each computer will have direct access to the other computers (unless using a partial which means some may only have direct access to some others instead of the whole).
47
What does OSI stand for?
Operation Systems interconnection
48
What is the OSI Model?
A theoretical way of classifying and talking about the complex process of sending data on a network.
49
What are the layers of the OSI Model?
7. Application
6. Presentation
5. Session
4. Transport
3. Network
2. Data Link
1. Physical
50
What does the Application layer of the OSI model do?
Integrates network functionality into the host operating system and enables communication between network clients and services.
51
True or False: Protocols for a layer can span multiple layers in in the OSI model.
True. Protocols are classified as the layer from which they start, regardless of how many layers they operate in.
52
What are the typical servers associated with the Application layer in the OSI model?
- HTTP
- Telnet
- FTP
- TFTP
- SNMP
53
What does the Presentation layer of the OSI model do?
Formats, or presents, data in a compatible form for receipt by the Application layer or the destination system:
- Formatting and translation of data between systems.
- Negotiation of data transfer syntax between systems by converting character sets to the correct format.
- Encapsulation of data into message envelopes by encryption and compression.
- Restoration of data by decryption and decompression.
54
What does the Session layer of the OSI model do?
Manages the sessions in which data are transferred:
- Management of multiple sessions (each client connection is called a session). A server can concurrently maintain thousands of sessions.
- Assignment of a session ID number to each session to keep data streams separate.
- The setup, maintenance, and teardown of communication sessions. (Connection Establishment)
55
What does the Transport layer of the OSI model do?
provides a transition between the upper and lower layers of the OSI model, making the upper and lower layers transparent from each other:
- End-to-end flow control.
- Port and socket numbers.
- Segmentation, sequencing, and combination.
- Connection services, either reliable (connection-oriented) or unreliable (connectionless) delivery of data.
56
What is another term for Data Segments in the Transport layer of the OSI model?
Segments
57
What does the Network layer of the OSI model do?
describes how data is routed across networks and on to the destination:
- Identifying hosts and networks by using logical addresses.
- Maintaining a list of known networks and neighboring routers.
- Determining the next network point where data should be sent. Routers use a routing protocol that takes various factors into account, such as the number of hops in the path, link speed, and link reliability, to select the optimal path for data.
58
What is another term for Data Segments in the Network layer of the OSI model?
Packets
59
What does the Data Link layer of the OSI model do?
Defines the rules and procedures for hosts as they access the Physical layer:
- How physical network devices are identified on the network by defining a unique hardware address (physical or MAC address).
- How and when devices have access to the LAN and can transmit on the network medium (media access control and logical topology).
- How to verify that the data received from the Physical layer is error free (parity and CRC).
- How devices control the rate of data transmission between hosts (flow control).
(*Identifying physical network devices, controlling how messages are propagated through the network.)
60
What is another term for Data Segments in the Data Link layer of the OSI model?
Frames
61
In what layer of the OSI model do Switches bridges, NICs, and WAPs function?
Data Link (Layer 2)
62
What does the Physical layer of the OSI model do?
Sets standards for sending and receiving electrical signals between devices:
- How digital data (bits) are converted to electric pulses, radio waves, or pulses of light and moved across network cables.
- Specifications for cables and connectors.
- The physical topology.
63
What is another term for Data Segments in the Physical layer of the OSI model?
Bits.
64
In what layer of the OSI model do NICs, repeaters, hubs, WAPs, and Modems function?
Physical (Layer 1)
65
What are the layers of the TCP/IP model?
- Application
- Host-to-Host
- Internet
- Network Access
66
Which layer(s) in the OSI model correspond to the Application layer in the TCP/IP model?
- Application (Layer 7)
- Presentation (Layer 6)
- Session (Layer 5)
67
Which layer(s) in the OSI model correspond to the Host-to-Host layer in the TCP/IP model?
Transport (layer 4)
68
Which layer(s) in the OSI model correspond to the Internet layer in the TCP/IP model?
Network (Layer 3)
69
Which layer(s) in the OSI model correspond to the Network Access layer in the TCP/IP model?
- Data Link (Layer 2)
| - Physical (Layer 1)
70
What are the two sublayers of the Data Link Layer of the OSI model?
- MAC (Media Access Control)
| - LLC (Logical Link Control)
71
What does the sublayer MAC do in the Data link layer of the OSI model?
Defines a unique MAC or data-link address for each device on the network. This address is usually assigned by the manufacturer. The MAC sublayer also provides devices with access to the network media.
(Lets devices on the network have access to the LAN, Defines a unique hardware address for each device on the network).
72
What does HTTP stand for?
Hypertext Transfer Protocol
73
What is HTTP used for?
Web browsers and web servers use HTTP to exchange files (such as web pages) through the world wide web and intranets.
74
What does SSL stand for?
Secure Sockets Layer
75
What does TLS stand for?
Transport Layer Security
76
What does TLS do?
Ensures that messages being transmitted on the internet are private and tamper proof. TLS is implemented through two protocols:
TLS Record can provide connection security with encryption (for example, with DES).
TLS Handshake provides mutual authentication and choice of encryption method.
77
What does SSL do?
Secures messages being transmitted on the internet. It uses RSA for authentication and encryption. Web browsers use SSL to ensure safe web transactions. URLs that begin with https:// trigger your web browser to use SSL.
78
What does FTP stand for?
File Transfer protocol
79
What does FTP do?
FTP provides a generic method for transferring files. It can protect access to files by requiring user names and passwords, and it allows file transfer between dissimilar computer systems. FTP can transfer both binary and text files, including HTML, to another host. FTP URLs are preceded by ftp:// followed by the DNS name of the FTP server. To log in to an FTP server, use ftp://username@servername.
* Does not use encryption
80
What does TFTP stand for?
Trivial File Transfer Protocol
81
What does TFTP do?
TFTP tranfers files between the host and am FTP server quickly, but without error detection or user authentication. More prone to transmission errors.
82
What does SFTP stand for?
Secure File Transfer Protocol
83
What does SFTP do?
Uses Secure Shell (SSH) to secure data transfers. SSH ensures that SFTP transmissions use encrypted commands and data, which prevents clear text data transmissions.
84
Does SCP stand for?
Secure Copy
85
What does SCP do?
Used to securely transfer files between systems. Like SFTP, SCP relies on SSH to ensure that data and passwords are not transmitted over the network in clear text.
86
What does SMTP stand for?
Simple Mail Transfer Protocol
87
What does SMTP do?
Used to route electronic mail through the internetwork. SMTP is used:
- Between mail servers for sending and relaying mail.
- By all email clients to send mail.
- By some email client programs, such as Microsoft Outlook, to receive mail from an Exchange server.
88
What does POP3 stand for?
Post Office Protocol 3
89
What does POP3 do?
Is used to retrieve email from a remote server and download it to a local client over a TCP/IP connection.
*Uses SMTP to send the mail.
90
What dose IMAP4 stand for?
Internet Message Access Protocol Version 4
91
What does IMAP4 do?
Is an email retrieval protocol designed to enable users to access their email from various locations without the need to transfer messages or files back and forth between computers. Messages remain on the remote mail server and are not automatically downloaded to a client system.
* uses SMTP to send mail
92
What does DHCP stand for?
Dynamic Host Configuration
93
What does DHCP do?
Used to automatically assign addresses and other configuration parameters to network hosts. Using a DHCP server, hosts receive configuration information at startup, reducing the amount of manual configuration required on each host.
94
What does DNS stand for?
Domain Name System
95
What dose a DNS do?
Is a distributed system throughout the internetwork that provides address and name resolution. For example, the name www.mydomain.com would be mapped to a specific IP address. (Takes an IP address and assigns a name to it for easier understanding on the users part)
96
What does NTP stand for?
Network Time Protocol
97
What does NTP do?
Is used to communicate time synchronization information between systems on a network.
98
What does LDAP stand for?
Lightweight Directory Access Protocol
99
What does LDAP do?
Used to search, retrieve data from, and update a directory service. The LDAP protocol follows a client/server model. One or more LDAP servers contain the directory data. The LDAP client connects to an LDAP Server to make a directory service request. By default, LDAP traffic is transmitted unsecured.
100
What is LDAPS?
LDAPS is the lightweight directory access protocol over TLS/SSL. Using LDAPS makes LDAP traffic confidential and secure.
101
What port does LDAPS use?
LDAPS uses TCP port 636.
102
What does SNMP stand for?
Simple Network Management Protocol
103
What does SNMP do?
Designed for managing complex networks. SNMP lets network hosts exchange configuration and status information. This information can be gathered by management software and is used to monitor and manage the network.
104
What is the function of Telnet?
Terminal Emulation (Telnet) Telnet allows a computer to remotely access the console of a computer system somewhere else in the network. At one time, Telnet was widely used for remote management tasks, but it is rarely used today. Because Telnet does not use encryption, it is recommended that you use a secure alternative to Telnet for remote management tasks, such as SSH.
105
What does SSH stand for?
Secure Shell
106
What does SSH do?
Allows for secure interactive control of remote systems. SSH uses RSA public key cryptography for both connection and authentication. SSH uses the IDEA algorithm for encryption by default, but it can use Blowfish and DES. SSH is a secure and preferred alternative to Telnet.
107
What does TCP stand for?
Transmission Control Protocol
108
Does does TCP do?
TCP provides services that ensure accurate and timely delivery of network communications between two hosts. TCP provides the following services to ensure message delivery:
- Sequencing of data packets
- Flow control
- Error checking
- Acknowledgement of packets sent
- Retransmission of lost packets
109
What does UDP stand for?
User Datagram Protocol
110
What does UDP do?
UDP is a host-to-host protocol like TCP, but it does not acknowledge each packet transmitted, nor does it allow for retransmission of lost packets. This reduces its overhead, allowing for faster communications and making UDP ideal for applications like streaming audio and video. However, this speed comes at the expense of possible errors or data loss.
* *(Faster than TCP, but comes with a cost of higher chance of errors.)
* *(Can use Connectionless datagram services)
111
What does ICMP stand for?
Internet Control Message Protocol
112
What does ICMP do?
ICMP works closely with IP to prevent errors and control information by allowing hosts to exchange packet status information. Two common management utilities, ping and traceroute, use ICMP messages to check network connectivity. ICMP also works with IP to send notices for the following:
- When destinations are unreachable
- Which route and hops a packet takes through the network
- Whether devices can communicate across the network
113
What does IGMP stand for?
Internet Group Management
114
What does IGMP do?
IGMP defines host groups. All group members can receive broadcast messages (multicasts) intended for the group. Multicast groups can be composed of devices within the same network or across networks (connected with a router).
