Firewall is a physical security device that cleaned in specs traffic coming from one network to a different network. A firewall is a system that implements an access control policy among two networks.
“Allows: http, mails etc. Keeps out: intruders, denial of services attacks etc.”
1.10.1 Firewall work: The protocol that computers use to be in touch on the internet is called TCP/IP.
Each computer on the Internet has a only one of its kind internet protocol and each computer has a run of ports used to be in touch with other computers
“Ex: http (web pages) – port 80 FTP (file) – port 21”
1.10.2 Need of firewall:
We require a firewall if we have a network (called a trusted network) which is linked to any other network (called an entrusted network) which does not fit in to us (like the internet)
Security it will discontinue most hackers from in advance access to the networks.
A firewall can do something …show more content…
One computer in Canada and second one in New Zealand
TCP/IP is also defining that how can data format and also give IP address to that data. It is also decide route of data means it’s also work with the help of router give path to data one computer to other computer.
1.11 DHCP (Dynamic Host Configuration Protocol) :
Whenever we want to configure a network we have to assign IP address to all computers in our network. If we are creating small network it is easy to assign an IP address manually but if we want to develop a large network we can assign IP address with the help of DHCP server. DHCP server provides automatically IP address to all computers and other information such as default gateway and DNS server address to the computers.
Now we assign IP address we have two options
1. Obtain an IP address automatically
This option we select when we create a large network.
2. Use the following IP address In this option we have three sub