STATIC AND DYNAMIC IP

Question 1

What are static ip addresses?

Answer 1

• Static IP Addresses are addresses that remain unchanged (ie fixed)
• They are often “manually” allocated and configured on hosts and can also be done automatically
• Even if the host is rebooted, the configured IP Address is still there as the host always has the same IP Address.

Question 2

State the pros and cons of static addresses.

Answer 2

PROS
* always the same IP address.
* contactable by other hosts

CONS
* laborious to manually assign IPs to large number of hosts
* high chance of configuring more than 1 host with the same IP
* may run out of IP address for every host
* troublesome to configure and release IPs to mobile hosts

Question 3

What is a dynamic ip addresses?

Answer 3

• Dynamic IP addresses are assigned by the network when a host is connected to the network
• The dynamic IP address allocated to a host may be different each time the host is connected to the network
• Dynamic IP addresses are temporarily allocated to a device and It is taken back when no longer needed

Question 4

What are the pros and cons of dynamic addresses?

Answer 4

Pros
* more efficient as IP address allocation and configuration are automatic
* re-allocation of the IP solves the IP scarcity issue
* suitable for mobile connectivity
* Eliminate IP address conflict

Cons
* Servers need to be readily contactable by client machines

Question 5

How to configure IP addresses through manual and automatic configuration?

Answer 5

MANUAL
* Pick a valid IP address and configure the host accordingly

AUTOMATIC
* Define a pool of usable IP addresses, and let the network decide which is to be allocated to a host.

Question 6

What is a network address?

Answer 6

• Network Address is an address in which all the host bits are ‘0’s.
• An address by which we refer to a network. This can be considered as Network ID or Subnetwork Identifier

Question 7

What is a broadcast address?

Answer 7

• Broadcast Address is an address in which all the host bits are ‘1’s.
• Broadcast Address is a special address that allows communication to all the hosts in that network

Question 8

What is a DHCP?

Answer 8

• DHCP is a client-server network management protocol that dynamically assigns to each device on the network an IP address and other network configuration information, so that they can communicate with other IP networks.
• When a host is connected to a network, the “DHCP client” service in the host makes a request (known as “DHCP Discovery”) with the DHCP server in the network for the network configuration information

Question 9

State the Disadvantages of DHCP

Answer 9

• Host joining the network will not be able to obtain an IP address if the DHCP server fails
• Unauthorised DHCP server offers addresses to users hence intercepting information over that connection leading to “man in the middle attack”.