This document discusses several commonly used application layer protocols including DNS, SMTP, FTP, POP, and HTTP. It explains the differences between SMTP, POP3, and IMAP which are email-related protocols. The internet layer protocols used include IP, ARP, and ICMP. Interior gateway protocols RIP and OSPF distribute routing information within an autonomous system, while exterior gateway protocol BGP distributes routing between autonomous systems. Optical fiber has advantages over copper wire including greater bandwidth, faster speeds, ability to transmit over longer distances, better reliability, thinner and sturdier cables, more flexibility for the future, and lower total cost of ownership. Key activities in the design phase of the SDLC include UI design review, technical design

1. 1, Name some commonly known application layer protocols.
 Domain Name System. The Domain Name System (DNS) works on Client Server model. ...
 Simple Mail Transfer Protocol. ...
 File Transfer Protocol. ...
 Post Office Protocol (POP) ...
 Hyper Text Transfer Protocol (HTTP)
. 2The protocols SMTP, POP3, and IMAP are e-mail-related protocols. What are the differ_ences among
t
An SMTP relay service can help you send email without having to build your own SMTP server. IMAP is
one of the most common protocols for receiving email. IMAP syncs messages across all devices. POP3 is
another protocol for receiving email on a single device
3What protocols are used in the internet layer?
Internet Layer. This layer, also known as the network layer, accepts and delivers packets for the
network. It includes the powerful Internet protocol (IP), the Address Resolution Protocol (ARP) protocol,
and the Internet Control Message Protocol (ICMP) protocol
5What is the difference between RIP OSPF and BGP?
OSPF and RIP are Interior Gateway Protocols (IGP) and distribute routing information within an
autonomous system, whereas BGP is a Exterior Gateway Protocol. The routes learned via the dynamic
routing protocols are applied to the kernel routing table.
6.What are the advantages of using optical Fibre compared with copper wire?
Advantages of Fiber Optic Cables Over Copper Cables
Greater Bandwidth. Copper cables were originally designed for voice transmission and have a limited
bandwidth. ...
Faster Speeds. ...
Longer Distances. ...
Better Reliability. ...
Thinner and Sturdier. ...

2. More Flexibility for the Future. ...
Lower Total Cost of Ownership.
6.What is the key activities in the design phase?
The key activities of the design phase in SDLC include User Interface (UI) design review,
technical design creation, and quality verification and validation
4.How are users categorized?
which means looking for groups of users that share similar goals, desires, needs, abilities, and
client-side environments.
9Unicast IP Address
When messages are exchanged between a sender and a receiver over a network, the information
exchange process is called unicast
Multicast
Multicast is for communication between a single sender and multiple receivers.
Anycast
Anycast is for the communication between any sender and one of the receivers in a group of hosts
Subnets
Subnetting is the process of dividing a network into several smaller networks.
Firwalls
Sudo ufw sataus
Sudo ufw enable
Sudo ufw allow 21
Sudo ufw delete allow 21
Sudo ufw allow 21/udp
Sudo ufw delete allow 21/udp
Sudo ufw deny smtp
Sudo ufw delete deny smtp
Sudo ufw disable

3. Vpn
Wget https://git.io/vpn -o openvpn-install/master/openvpn-install.sh
Chmod +x openvpn-install.sh
Openvpn-install.sh
Sudo ufw status
Sudo ufw enable
Sudo ufw status
Sudo ufw allow 1194/udp
Sudo ufw status
Sudo natstat- apt/group openvpn
sU
Ls-l
Sudo apt-get install network-manger-openvpn