Transport layer

Question 1

what does transport layer do?

Answer 1

transport layer allows traffic to be directed to a specific network application.

Question 2

what is port

Answer 2

they are 16 bit number that is used to direct traffic to a specific services running on a networked computer

Question 3

what flags are present i a TCP header

Answer 3

URG(urgent) : segment is considered urgent.
ACK: ack number field should be examined.
PSH( push) : push the data as soon as possible
RST (reset) : to forcefully terminate a connection.
syn ( synchronize) : used in the initial three-way handshake.
fin(finish) : connection can be closed.

Question 4

port numbers

Answer 4

system ports : 1 - 1023
user ports : 1024 - 49151
dynamic / private port : 49152 - 65535

Question 5

how firewall works

Answer 5

there are two ways in which a firewall works:
1]. packet filtering : Data is organized in packets. firewall examines the packets of data, comparing it against filters, which consist of information used to identify malicious data. If a data packet meets the parameters of a threat as defined by a filter, then it is discarded and your network is protected.
2]. Proxy server: it acts as a go-between , between your computer and anyone that is trying to attack your computer.

Question 6

what is a firewall

Answer 6

A firewall is either a hardware device or a software application that helps protect your network from attackers. The firewall shields your network by acting as a 24/7 filter, scanning the data that attempts to enter your network and preventing anything that looks suspicious from getting through.