IT Interview Questions:How ARP Works ?

When an incoming packet destined for a host machine on a particular local
area network arrives at a gateway, the gateway asks the ARP program to find a
physical host or MAC address that matches the IP address. The ARP program
looks in the ARP cache and, if it finds the address, provides it so that the
packet can be converted to the right packet length and format and sent to the
machine. If no entry is found for the IP address, ARP broadcasts a request
packet in a special format to all the machines on the LAN to see if one
machine knows that it has that IP address associated with it. A machine that
recognizes the IP address as its own returns a reply so indicating. ARP
updates the ARP cache for future reference and then sends the packet to the
MAC address that replied.
Since protocol details differ for each type of
local area network, there are separate ARP Requests for Comments (RFC) for
Ethernet, ATM, Fiber Distributed-Data Interface, HIPPI, and other protocols.
There is a Reverse ARP (RARP) for host machines that don't know their IP
address. RARP enables them to request their IP address from the gateway's ARP
cache. RARP (Reverse Address Resolution Protocol) is a protocol by which a
physical machine in a local area network can request to learn its IP address
from a gateway server's Address Resolution Protocol (ARP) table or cache. A
network administrator creates a table in a local area network's gateway
router that maps the physical machine (or Media Access Control



MAC address) addresses to corresponding Internet Protocol addresses. When a
new machine is set up, its RARP client program requests from the RARP server
on the router to be sent its IP address. Assuming that an entry has been set
up in the router table, the RARP server will return the IP address to the
machine which can store it for future use.

IT Interview Questions:What is ARP?

What is ARP Cache Poisoning?
Address Resolution Protocol (ARP) is a protocol
for mapping an Internet Protocol address (IP address) to a physical machine
address that is recognized in the local network. For example, in IP Version
4, the most common level of IP in use today, an address is 32 bits long. In
an Ethernet local area network, however, addresses for attached devices are
48 bits long. (The physical machine address is also known as a Media Access
Control or MAC address.) A table, usually called the ARP cache, is used to
maintain a correlation between each MAC address and its corresponding IP
address. ARP provides the protocol rules for making this correlation and
providing address conversion in both directions.

IT Interview Questions:What is subnet Mask ?

A subnet (short for "subnetwork") is an identifiably separate part of an
organization's network. Typically, a subnet may represent all the machines at
one geographic location, in one building, or on the same local area network
(LAN). Having an organization's network divided into subnets allows it to be
connected to the Internet with a single shared network address. Without
subnets, an organization could get multiple connections to the Internet, one
for each of its physically separate subnetworks, but this would require an
unnecessary use of the limited number of network numbers the Internet has to
assign. It would also require that Internet routing tables on gateways
outside the organization would need to know about and have to manage routing
that could and should be handled within an organization.

IT Interview Questions: What is an IP address?

Every device connected to the public Internet is assigned a unique number
known as an Internet Protocol (IP) address. IP addresses consist of four
numbers separated by periods (also called a 'dotted-quad') and look something
like 127.0.0.1. In computer networking, an Internet Protocol (IP) address
consists of a numerical identification (logical address) that network
management assigns to devices participating in a computer network utilizing
the Internet Protocol for communication between its nodes.
[1]
Although
computers store IP addresses as binary numbers, they often display them in
more human-readable notations, such as 192.168.100.1 (for IPv4), and
2001:db8:0:1234:0:567:1:1 (for IPv6). The role of the IP address has been
characterized as follows: "A name indicates what we seek. An address
indicates where it is. A route indicates how to get there."

IT Interview Questions:What are the greatest threats to ....


What are the greatest threats to the effectiveness and efficiency of state government IT services and/or state government service delivery in the next twelve months?
In the next 24 months?
What needs to be done in these organizations (or elsewhere) to minimize the risks to the state?

· The Information Technology Commission (ITC)
· The Information Technology Management Office
· GSD/ISD
· Agency IT support organization(s)

IT Interview Questions:Where are the greatest opportunities ...

Where are the greatest opportunities for improving state government IT services and state government service delivery in the next twelve months?
In the next 24 months?
How can the most money be saved?
How can the greatest service improvements be realized?
What needs to be done in these organizations (or elsewhere) to realize these improvements?

· The Information Technology Commission (ITC)
· The Information Technology Management Office
· GSD/ISD
· Agency IT support organization(s)

IT Interview Questions: What doesn't work well.....


What doesn't work well in New Mexico State Government with respect to the IT services and/or capabilities of the following organizations?
What's wrong and should be eliminated, reduced or replaced?

· The Information Technology Commission (ITC)
· The Information Technology Management Office
· GSD/ISD
· Agency IT support organization(s)

IT Interview Questions: What works well ....




What works well in New Mexico State Government with respect to the IT services and capabilities in the following organizations?


What's right and should be continued, expanded, or more actively supported?

· The Information Technology Commission (ITC)
· The Information Technology Management Office
· GSD/ISD
· Agency IT support organization(s)

IT Interview Questions: Do you consider your organization to have an role in delivering....

1. Do you consider your organization to have an role in delivering or supporting IT services for state government as an institution (i.e. is your role broader than a specific agency or program?).
If so, what is your role and your organization's mission statement?

How to Succeed in your IT Interview

So, how would you answer tough interview questions such as 'What are your weaknesses?' or 'Why should we hire you instead of the other candidates?'.

And, how confident do you feel about answering Competency Based or Behavioural questions, both very commonly used at present.