Understanding Web Applications and Internet Services
Web Applications and Internet Services
The Internet World
Definition: The Internet is a global network of shared devices (PCs, printers, hard drives, etc.) that communicate using a common language (protocol) to exchange information.
History: The Internet originated with ARPANET in the USA.
Connecting to the Internet: You connect through an ISP (Internet Service Provider).
Internet Services
Web Navigation
Accessing web pages located on websites. The first page you see is the home page (index, home, rate.
Read MoreVPNs, Security Associations, WEP, EAP, and Firewalls
Virtual Private Networks (VPNs)
Motivation: Institutions often want private networks for security. This traditionally involved costly separate routers, links, and DNS infrastructure. A VPN provides a solution where an institution’s inter-office traffic is sent over the public Internet but is made secure.
- Traffic is encrypted before entering the public Internet.
- Traffic is logically separate from other traffic, creating a secure tunnel.
Security Associations (SAs)
- Before sending data, a Security Association
Networking Exam Questions and Answers
Midterm 1
1. Which of the following is an application layer service?
D) Remote log-in, File transfer and access, mail service.
2. You want to implement a mechanism that automates the IP configuration, including IP address, subnet mask, default gateway, and DNS information. Which protocol will you use?
C) DHCP.
3. Internet Control Message Protocol (ICMP):
A) Reports error conditions to the original source; the source must relate errors to individual application.
4. What technique is used for fragmentation?
Read MoreNetwork Address Translation (NAT): Benefits and Uses
Network Address Translation (NAT) Explained
Network Address Translation (NAT) is a method of remapping one IP address space to another. This is done to conserve public IP addresses, which are a limited resource. NAT is used in many modern network environments, including home networks, businesses, and cellular networks.
NAT in Business Networks
NAT is also used in businesses to connect multiple devices to the internet using a single public IP address. This improves security and reduces the workload
Read MoreUnderstanding Network Layers and Protocols
Network Layers Explained
Application Layer
- Defines the interfaces between the software application and communication functions of the network.
- Provides standardized services such as file transfer between systems.
Session Layer
- Manages user sessions and dialogues.
- Manages links between applications.
Network Layer
- Provides logical network addressing.
- Routes packets between networks by following a logical addressing scheme.
Physical Layer
- Defines the physical means to send data over network devices.
- Acts as an
DNS, DHCP, SSH, Proxy, HTTP, Email, FTP, and IRC Explained
Understanding Key Internet Protocols
DNS (Domain Name System) translates domain names to IP addresses, locating websites. Examples of domain extensions include:
- .com – Commercial
- .org – Organization
- .edu – Educational
- .net – Internet and communications
- .gov – Governmental organizations
Domain delegation decentralizes DNS database administration. Reverse resolution returns a hostname given an IP address.
DHCP (Dynamic Host Configuration Protocol)
DHCP offers fast network configuration to clients. Allocation
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