Networking:
1) What is ip address.
Ip address are used to identify the computers uniquely in the network.
2) Subnet mask:
Part of an IP address identifies the network. The other part of the address
identifies the host. A subnet mask is required to provide this distinction:
158.80.164.3 255.255.0.0
The above IP address has a subnet mask of 255.255.0.0. The subnet mask
follows two rules:
• If a binary bit is set to a 1 (or on) in a subnet mask, the corresponding
bit in the address identifies the network.
• If a binary bit is set to a 0 (or off) in a subnet mask, the corresponding
bit in the address identifies the host.
Looking at the above address and subnet mask in binary:
IP Address: 10011110.01010000.10100100.00000011
Subnet Mask: 11111111.11111111.00000000.00000000
identifies the host. A subnet mask is required to provide this distinction:
158.80.164.3 255.255.0.0
The above IP address has a subnet mask of 255.255.0.0. The subnet mask
follows two rules:
• If a binary bit is set to a 1 (or on) in a subnet mask, the corresponding
bit in the address identifies the network.
• If a binary bit is set to a 0 (or off) in a subnet mask, the corresponding
bit in the address identifies the host.
Looking at the above address and subnet mask in binary:
IP Address: 10011110.01010000.10100100.00000011
Subnet Mask: 11111111.11111111.00000000.00000000
3)Subnet and Broadcast Addresses.
On each IP network, two host addresses are reserved for special use:
• The subnet (or network) address
• The broadcast address
Neither of these addresses can be assigned to an actual host.
The subnet address is used to identify the network itself. A routing table
contains a list of known networks, and each network is identified by its
subnet address. Subnet addresses contain all 0 bits in the host portion of
the address.
For example, 192.168.1.0/24 is a subnet address. This can be determined by
looking at the address and subnet mask in binary:
IP Address: 11000000.10101000.00000001.00000000
Subnet Mask: 11111111.11111111.11111111.00000000
Note that all host bits in the address are set to 0.
The broadcast address identifies all hosts on a particular network. A packet
sent to the broadcast address will be received and processed by every host on
that network. Broadcast addresses contain all 1 bits in the host portion of
the address.
For example, 192.168.1.255/24 is a broadcast address. Note that all host bits
are set to 1:
IP Address: 11000000.10101000.00000001.11111111
Subnet Mask: 11111111.11111111.11111111.00000000
Broadcasts are one of three types of IP packets:
• Unicasts are packets sent from one host to one other host
• Multicasts are packets sent from one host to a group of hosts
• Broadcasts are packets sent from one host to all other hosts on the
local network
4) what is default gateway.
a default gateway is the device that passes traffic from the local subnet to devices on other subnets. The default gateway often connects a local network to the Internet, although internal gateways for local networks also exist.
5) Define Network.
A network is a group of two or more computer systems linked together.
Three types of Network:
LAN
WAN
MAN
Three types of Network:
LAN
WAN
MAN
6) What is a Link.
7) What is a node.
8) What is Multiple Access.
If the physical links are shared by more than two nodes, it is said to be Multiple Access.9) What is Protocol.
A protocol is a set of rules that govern all aspects of information communication.
10) Define OSI model, which are the layers? (in Sequence)
The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers.
11) What are the concerns of the Physical Layer.
Physical layer coordinates the functions required to transmit a bit stream over a physical medium.a. Physical characteristics of interfaces and media
b. Representation of bits
c. Data rate
d. Synchronization of bits
e. Line configuration
f. Physical topology
g. Transmission mode
12) What are the responsibilities of Data Link Layer.
The Data Link Layer transforms the physical layer, a raw transmission facility, to a reliable link and is responsible for node-node delivery.a. Framing
b. Physical Addressing
c. Flow Control
d. Error Control
e. Access Control
13) What are the responsibilities of Network Layer.
The Network Layer is responsible for the source-to-destination delivery of packet possibly across multiple networks (links).a. Logical Addressing
b. Routing
14) What are the responsibilities of Transport Layer.
The Transport Layer is responsible for source-to-destination delivery of the entire message.a. Service-point Addressing
b. Segmentation and reassembly
c. Connection Control
d. Flow Control
e. Error Control
15) What are the responsibilities of Session Layer.
The Session layer is the network dialog Controller. It establishes, maintains and synchronizes the interaction between the communicating systems.a. Dialog control
b. Synchronization
16) What are the responsibilities of Presentation Layer.
The Presentation layer is concerned with the syntax and semantics of the information exchanged between two systems.a. Translation
b. Encryption
c. Compression
17) What are the responsibilities of Application Layer.
The Application Layer enables the user, whether human or software, to access the network. It provides user interfaces and support for services such as e-mail, shared database management and other types of distributed information services.a. Network virtual Terminal
b. File transfer, access and Management (FTAM)
c. Mail services
d. Directory Services
18) What is the difference between static and dynamic routes.
Static routes are routes that an administrator manually enters into a router. Dynamic routes are routes that a router learns automatically through a routing protocol.
19) private range of ip address.
Private :
10.0.0.0 through 10.255.255.255
169.254.0.0 through 169.254.255.255 (APIPA only)
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255
169.254.0.0 through 169.254.255.255 (APIPA only)
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255
20) Classes of IP address.
| Class A | 1.0.0.1 to 126.255.255.254 | Supports 16 million hosts on each of 127 networks. |
| Class B | 128.1.0.1 to 191.255.255.254 | Supports 65,000 hosts on each of 16,000 networks. |
| Class C | 192.0.1.1 to 223.255.254.254 | Supports 254 hosts on each of 2 million networks. |
| Class D | 224.0.0.0 to 239.255.255.255 | Reserved for multicast groups. |
| Class E | 240.0.0.0 to 254.255.255.254 | Reserved for future use, or Research and Development Purposes. |
21) Diffrence between hub, switch and routers.
Hub
for communication. Hubs can also be referred to as repeaters
Switch
Using this information, Layer-2 devices will make intelligent forwarding
decisions based on frame (Data-Link) headers. A frame can then be
forwarded out only the appropriate destination port, instead of all ports.
Manageable Switches operates at Layer 3(Network Layer)
Router
another network, based on the Network-layer header. Routers build routing
tables to perform forwarding decisions.
22) What is a broadcast address.
In computer networking, a broadcast address is an IP address that allows information to be sent to all machines on a given subnet rather than a specific machine.
Last ip address of the ip
23) How to configure reverse lookup zone in DNS.
Go to DNS server and right click on reverse look up zone and create reverse lookup zone.
24) What is FTP.
FTP stands for File Transfer Protocol. This is one of the most common ways to upload and download files from your server.
FTP uses port 21
SFTP:
Secure file transfer protocol(sftp) is a terminal program that encrypts the files that you send and recievei to a remote system.
sftp uses port 22
25) Remote Desktop and Remote Assistance.
Use Remote Desktop to access one computer from another remotely. For example, you can use Remote Desktop to connect to your work computer from home. You will have access to all of your programs, files, and network resources, as if you were sitting in front of your computer at work. While you are connected, the remote computer screen will appear to be blank to anyone at the remote location who sees it.
26) Difference between TCP and UDP.
TCP
|
UDP
|
Reliability: TCP is connection-oriented protocol. When a file or message send it will get delivered unless connections fails. If connection lost, the server will request the lost part. There is no corruption while transferring a message.
|
Reliability: UDP is connectionless protocol. When you a send a data or message, you don't know if it'll get there, it could get lost on the way. There may be corruption while transferring a message.
|
Ordered: If you send two messages along a connection, one after the other, you know the first message will get there first. You don't have to worry about data arriving in the wrong order.
|
Ordered: If you send two messages out, you don't know what order they'll arrive in i.e. no ordered
|
Heavyweight: - when the low level parts of the TCP "stream" arrive in the wrong order, resend requests have to be sent, and all the out of sequence parts have to be put back together, so requires a bit of work to piece together.
|
Lightweight: No ordering of messages, no tracking connections, etc. It's just fire and forget! This means it's a lot quicker, and the network card / OS have to do very little work to translate the data back from the packets.
|
Streaming: Data is read as a "stream," with nothing distinguishing where one packet ends and another begins. There may be multiple packets per read call.
|
Datagrams: Packets are sent individually and are guaranteed to be whole if they arrive. One packet per one read call.
|
Examples: World Wide Web (Apache TCP port 80), e-mail (SMTP TCP port 25 Postfix MTA), File Transfer Protocol (FTP port 21) and Secure Shell (OpenSSH port 22) etc.
|
Examples: Domain Name System (DNS UDP port 53), streaming media applications such as IPTV or movies, Voice over IP (VoIP), Trivial File Transfer Protocol (TFTP) and online multiplayer games etc
|
27) Difference between TCP and IP.
TCP and UDP belongs to layer 4 ie: Transport layer
IP belongs to layer 3 ie: Network layer
Port Numbers:
FTP = 21
SFTP = 22
Telnet = 23
SMTP = 25, ssl = 465
DNS = 53
HTTP = 80
HTTPS = 443
IMAPS = 993
POP3 = 110
WINS = 42
DHCP = 68 and 67
LDAP = 389
pop3 = 110
IMAP = 143, ssl= 993
RDP = 3389
28) The Difference Between IPv6 and IPv4 IP Addresses
An IP address is binary numbers, 32-bit numeric address (IPv4) is written in decimal as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.IPv6 addresses are 128-bit IP address written in hexadecimal and separated by colons. An example IPv6 address could be written like this: 3ffe:1900:4545:3:200:f8ff:fe21:67cf
29) Difference between SSL and SSH.
SSL: Stands for Secure sockets layer and it uses port 443 to connect your computer to a secure server on the Internet. SSL is most often used for transmitting credit card, tax, banking, or personal information to a business server somewhere
SSH: Stands for Secure shell and it uses port 22 to connect your computer to another computer on the Internet. It is most often used by network administrators as a remote login / remote control way to manage their business servers.
30) Define LAN.
A LAN is generally a high-speed network that covers a small geographic
area, usually contained within a single building or campus.
31) Define WAN
WAN is a network that spans large geographical locations, usually to connect multiple LANs.
32)Define MAN.
A MAN is defined as a network that connects LAN’s across a city-wide geographic area.
33) What is ARP table.
A host can build an ARP table that contains a list of IP to MAC address
translations. The ARP table is only locally significant to that host. There are
two methods to populate an ARP table:
• Statically
• Dynamically
A static ARP entry is created manually on a host, and will remain
permanently until purposely removed. More commonly, ARP tables are built
dynamically by caching ARP replies. Cached entries will eventually be
aged out of the ARP table. The aging time will vary depending on the
operating system, and can range from several seconds to several hours.
34) What Is topology.
Topology is the physical layout of the Networking devices on the network.
Types of Topology
bus
30) Define LAN.
A LAN is generally a high-speed network that covers a small geographic
area, usually contained within a single building or campus.
31) Define WAN
WAN is a network that spans large geographical locations, usually to connect multiple LANs.
32)Define MAN.
A MAN is defined as a network that connects LAN’s across a city-wide geographic area.
33) What is ARP table.
A host can build an ARP table that contains a list of IP to MAC address
translations. The ARP table is only locally significant to that host. There are
two methods to populate an ARP table:
• Statically
• Dynamically
A static ARP entry is created manually on a host, and will remain
permanently until purposely removed. More commonly, ARP tables are built
dynamically by caching ARP replies. Cached entries will eventually be
aged out of the ARP table. The aging time will vary depending on the
operating system, and can range from several seconds to several hours.
34) What Is topology.
Topology is the physical layout of the Networking devices on the network.
Types of Topology
bus
Star
Ring
35) What is PING Utility.
PING – Packet Internet Gopher A utility that verifies connections to one or more remote hosts.
36) What are 10Base2, 10Base5 and 10BaseT Ethernet LANs?
10Base2 an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 200 meters (185mts). Known as Thinnet.
10Base5 an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 500 meters. Known as Thicknet.
10BaseT an Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses two pairs of twisted-pair baseband signaling, with a contiguous cable segment length of 100 meters.
37) Difference between the Communication and Transmission?
Communication is the process of sending and receiving data by means of a data cable that is connected externally.
Transmission means the transfer of data from the source to the destination.
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