Category Archives: System Administration

Explain the importance of IP addressing and how can you classify it to represent IP address.

An IP address is an address used to uniquely identify a device on an IP network. The address is made up of 32 binary bits which can be divisible into a network portion and host portion with the help of a subnet mask. The 32 binary bits are broken into four octets (1 octet = 8 bits). Each octet is converted to decimal and separated by a period (dot). For this reason, an IP address is said to be expressed in dotted decimal format (for example, 172.16.81.100). The value in each octet ranges from 0 to 255 decimal, or 00000000 – 11111111 binary.

Classification of IP Address

In a Class A address, the first octet is the network portion, so the Class A has a major network address of 1.0.0.0 – 127.255.255.255. Octets 2, 3, and 4 (the next 24 bits) are for the network manager to divide into subnets and hosts as he/she sees fit. Class A addresses are used for networks that have more than 65,536 hosts (actually, up to 16777214 hosts!).

In a Class B address, the first two octets are the network portion, so the Class B has a major network address of 128.0.0.0 – 191.255.255.255. Octets 3 and 4 (16 bits) are for local subnets and hosts. Class B addresses is used for networks that have between 256 and 65534 hosts.

In a Class C address, the first three octets are the network portion.
The Class C has a major network address of 192.0.0.0 – 233.255.255.255. Octet 4 (8 bits) is for local subnets and hosts – perfect for networks with less than 254 hosts.

Network Masks:
A network mask helps you know which portion of the address identifies the network and which portion of the address identifies thenode. Class A, B, and C networks have default masks, also known as natural masks, as shown here:
Class A: 255.0.0.0 —–/8
Class B: 255.255.0.0 —/16
Class C: 255.255.255.0–/24

What are the different types of disasters? Explain in brief how can you develop disaster recovery plan?

The different types of disasters can be classified into two categories. They are:

Natural disasters
A natural disaster is a major adverse event resulting from the earth’s
natural hazards. Examples of natural disasters are floods,
tsunamis, tornadoes, hurricanes/cyclones, volcanic
eruptions, earthquakes, heat waves, and landslides.

Man-made disasters
Man-made disasters are the consequence of technological or human
hazards. Examples include stampedes, urban fires, industrial
accidents, oil spills, nuclear explosions/nuclear radiation and acts
of war.

Develop disaster recovery plan

Step1: Risk Analysis
The first step in drafting a disaster recovery plan is conducting a
thorough risk analysis of our computer systems. List all the possible
risks that threaten system uptime and evaluate how imminent they are in our particular IT shop.

Step 2: Establish the Budget
Once you’ve figured out your risks, ask ‘what can we do to suppress them, and how much will it cost?’

Step 3: Develop the Plan 
The feedback from the business units will begin to shape your DRP procedures. The recovery procedure should be written in a detailed plan or “script.” Establish a Recovery Team from among the IT staff and assign specific recovery duties to each member and Define how to deal with the loss of various aspects of the network and specify who arranges for repairs or reconstruction and how the data recovery process occurs.

Step 4: Test
Once your DRP is set, test it frequently. Eventually you’ll need to
perform a component-level restoration of your largest databases to get a realistic assessment of your recovery procedure, but a periodic
walk-through of the procedure with the Recovery Team will assure
that everyone knows their roles.