qa for interview (1)

7/28/2019 QA for Interview (1)

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Why We Need IP Address?

IP address (Internet Protocol) is a numerical label assigned to each device (e.g., computer, printer)

participating in a computer network that uses the Internet Protocol for communication. An IP address

serves two principal functions: host or network interface identification and location addressing. Its role

has been characterized as follows:

"A name indicates what we seek. An address indicates where it is. A route indicates how to get there."

Types of IP Address?

Static IP Address

Dynamic IP Address

Class of IP Address & its range?

Class

Leading Range of

address bits first octet

A 0 1 - 126

B 10 128 – 191

C 110 192 – 223

Private Address:

Start End

24-bit Block (/8 prefix, 1 × A) 10.0.0.0 10.255.255.25520-bit Block (/12 prefix, 16 × B) 172.16.0.0 172.31.255.255

16-bit Block (/16 prefix, 256 × C) 192.168.0.0 192.168.255.255

Default IP Address?

APIPA?

Automatic Private Internet Protocol Addressing (APIPA) is a common alternative to the use of the

Dynamic Host Configuration Protocol (DHCP) to request and retrieve an Internet Protocol (IP) address

for a host. APIPA simplifies the assignment of IP address and subnet-mask configuration information to

hosts in small networks. When APIPA is used, the operating system allows the assignment of a unique IP

address to each station on a small local area network (LAN). This avoids the administrative overhead of running a DHCP server or manually setting IP configuration information. APIPA is a procedure and set of

guidelines for performing these configuration functions, not an actual protocol. It first appeared on the

Windows platform in Windows 2000.

Command to Release IP Address and its Function?

If the computer is holding a current IP address, type 'ipconfig /release' to let go of the address.



Command to renew IP address?

Type 'ipconfig /renew' to obtain a new IP address (whether or not the computer is holding a current

address).

What is a Default Gateway?

A default gateway is the node on the computer network that the network software uses when an IP

address does not match any other routes in the routing table. The default gateway commonly connects

the internal networks and the outside network (Internet). In such a situation, the gateway node could

also act as a proxy server and a firewall. The gateway is also associated with both a router, which uses

headers and forwarding tables to determine where packets are sent, and a switch, which provides the

actual path for the packet in and out of the gateway.

How to disable the proxy setting?

In IE tool Internet options Connections Lan Setting Uncheck Proxy server option

How to get IP address detail?

Start Run cmd in command prompt type ipconfig /all

1. If I have to connect to individual computer or machine to each other, So what are the

requirement for that?

Physical Level/ address:

LAN Cable/ Ethernet Cable

NIC Card with activated status

RJ 45 Jack

Colour Coding

Logical address:

IP Address

2. What is Loop Back Address?

127.0.0.13. Difference between routers and switches?

4. what is Logical Address? Size of MAC & IP Address

5. What is DHCP? DORA? APIPA? Their Function

6. Size of MAC address, IP Address.

7. NS Lookup



1. What is Logical Address?

The network interface card or any networking component has 2 addresses, one is physically embedded

on the hardware known as MAC address and the IP address ....here the IP address becomes the logical

entity which is no where embedded . Being a logical entity, it can be changed as wished unlike Mac

address.

3. What is MAC address? Where can u find the MAC address? Size of MAC address, IP Address

Mac address is the physical address is 48 bit in length, represented in hexadecimal format. In any

windows machine, if ipconfig is executed in command prompt, it displays the mac address.

Ip address is 32 bit in length, there are two versions of IP addresses IPv4 and IPv6 , similar to mac

address IPconfig displays the IP configured on machine.

IFconfig is used in linux machine to check ip stack.

4. DHCP: Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that automatically

provides an Internet Protocol (IP) host with its IP address and other related configuration information

such as the subnet mask and default gateway. DHCP allows hosts to obtain necessary TCP/IPconfiguration information from a DHCP server.

5. DNS : Domain Name System (DNS) is one of the industry-standard suite of protocols that comprise

TCP/IP. Network resources are identified by numeric IP addresses, but these IP addresses are difficult for

network users to remember. The DNS database contains records that map user-friendly alphanumeric

names for network resources to the IP address used by those resources for communication. In this way,

DNS acts as a mnemonic device, making network resources easier to remember for network users.

6 . DORA : DORA stands for discover , offer , request and acknowledgement. when we install a dhcp

server into our network then dhcp server works on the basis of dora process

first dhcp server sends a hello message in to the network to discover the clients pc and when any client

pc found in the network then , dhcp server offers the IP to client pc. When client pc select any IP from

dhcp server then client pc request for selected IP to dhcp server then dhcp server provide that IP to

client pc and both send ackonledgement to each other.

This process is called DORA process on the basis of this process DHCP server works to provide IP's

dynamically to client pc's in network

7. NSLOOKUP : nslookup is the name of a program that lets an Internet server administrator or any

computer user enter a host name (for example, "whatis.com") and find out the corresponding IP

address. It will also do reverse name lookup and find the host name for an IP address you specify.

Ns lookup is a tool used for domain name against the IP address. Nslookup depends on dns server

addresses configured on machine, and when executed nslookup queries these dns server for the

authorititive response for domain and responds with IPs associated with domain names.

8. Cable Unplug : If your network is not functioning properly, you may see "A Network Cable Is

Unplugged" messages appear repeatedly on the Windows desktop. Messages may pop up on the screen

once every few days or even once every few minutes depending on the nature of the problem. This can

occur even if you are using a WiFi wireless network.



What is Full form of ADS?

Active Directory Structure

How will you register and activate windows?

If you have not activated windows XP, you can do so at any time by clicking the windows Activation

icon in the system tray to initiate activation. Once you have activated windows XP, this icon disappears

from the system tray.

For registration

Start ==> Run ==> regwiz /r

Where do we use cross and standard cable?Computer to computer ==> cross

Switch/hub to switch/hub ==>cross

Computer to switch/hub ==>standard

How many pins do serial ports have?

In computer it’s known as com port and could be available in 9pin or 25 pin. On router it have 60 pins.

How will check ip address on 98?

Start ==> Run ==> command ==> winipcfg

How will you make partition after installing windows?

My computer ==> right click ==> manage ==> disk management ==>

select free space ==> right click ==> New partition

What is IP?

It’s a unique 32 bits software address of a node in a network.

What is private IP?

Three ranges of IP addresses have been reserved for private address and they are not valid for use on the

Internet. If you want to access internet with these address you must have to use proxy server or NAT

server (on normal cases the role of proxy server is played by your ISP.).If you do decide to implement a

private IP address range, you can use IP addresses from any of the following classes:

Class A 10.0.0.0 10.255.255.255

Class B 172.16.0.0 172.31.255.255

Class C 192.168.0.0 192.168.255.255

What is public IP address?

A public IP address is an address leased from an ISP that allows or enables direct Internetcommunication.



What’s the benefit of subnetting?

Reduce the size of the routing tables.

Reduce network traffic. Broadcast traffic can be isolated within a single logical network.

Provide a way to secure network traffic by isolating it from the rest of the network.

What are the differences between static ip addressing and dynamic ip addressing?

With static IP addressing, a computer (or other device) is configured to always use the same IP address.With dynamic addressing, the IP address can change periodically and is managed by a centralizednetwork service

What is APIPA?

Automatic private IP addressing (APIPA) is a feature mainly found in Microsoft operating systems.APIPA enables clients to still communicate with other computers on the same network segment until anIP address can be obtained from a DHCP server, allowing the machine to fully participate on the network.The range of these IP address are the 169.254.0.1 to 169.254.255.254 with a default Class B subnet mask

of 255.255.0.0.

What are the LMHOSTS files?

The LMHOSTS file is a static method of resolving NetBIOS names to IP addresses in the same way thatthe HOSTS file is a static method of resolving domain names into IP addresses. An LMHOSTS file is atext file that maps NetBIOS names to IP addresses; it must be manually configured and updated.

What is DHCP scope?

A scope is a range, or pool, of IP addresses that can be leased to DHCP clients on a given subnet.

What is FQDN?

An FQDN contains (fully qualified domain name) both the hostname and a domain name. It uniquelyidentifies a host within a DNS hierarchy

What is the DNS forwarder?

DNS servers often must communicate with DNS servers outside of the local network. A forwarder is anentry that is used when a DNS server receives DNS queries that it cannot resolve locally. It then forwards

those requests to external DNS servers for resolution.

Why do we need ip address when the mac address is unique? Can't we communicate only with mac

address?

MAC address is the basis on which communication occurs.However we need IP address to be able to

create a routing table ,that enables faster commnication.Lots of communication algorithms take use of IP

address ( Network address +SubNet masks) to be able to route packages faster.

http://www.geekinterview.com/question_details/45556







We need I.P address because when we work on LAN we can communicate without I.P address with the

help of NETBIOS and WINS but in WAN we work on network layer and data frame becomes packet and

packet need I.P address for routing.

Why do we use subnet mask? What are its uses?

Subnetmask is use to isolate the network ID and Host ID. eg- if an IP is:192.168.0.1 then the default

subnet is:255.255.255.0 because it is a C Class Address C Class Add. have 3 network octate and 1 host

octate i.e.

network ID :192.168.0.0

host ID : 0.0.0.1




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