Understanding Network Types, Connections, and Protocols
Understanding Network Types and Connections
Network types depend on the geographical size they cover.
1. LAN (Local Area Network)
A LAN covers a single geographical area. Typically, all computers within a LAN belong to the same organization. LANs offer several benefits:
- Allow users to log in from any part of the organization.
- Enable easy data sharing.
- Help manage systems efficiently.
- Facilitate user collaboration.
2. WLAN (Wireless LAN)
A WLAN connects devices wirelessly. It requires special security measures
Read MoreNetworking Fundamentals: Key Concepts and Troubleshooting
IPv4 Routing
In an IPv4 environment, what address is used by the router to send packets of data over a router interface to another? Destination network address
OSI Layer 3 Encapsulation
What addresses are added during encapsulation at OSI Layer 3? Source and destination IP addresses
Connectionless Systems
In a system without connection, which of the following is correct? The destination is not contacted before sending the packet
IP Packet Loop Prevention
What field of an IP packet prevents endless loops?
VPNs, Firewalls, and Network Security Essentials
Virtual Private Networks (VPNs)
Motivation: Institutions often want private networks for security. However, maintaining separate routers, links, and DNS infrastructure can be costly. A VPN offers a solution by creating a secure tunnel over the public internet. With a VPN, an institution’s inter-office traffic is sent over the public internet but is:
- Encrypted before entering the public internet
- Logically separated from other traffic
Security Associations (SAs)
- Before sending data, a “security association
Understanding IPv6, Client/Server, DNS, IP, and NAT
How IPv6 Works
- IPv6 has more address space because it uses 128 bits, whereas IPv4 uses only 32 bits for its IP address.
- IPv6 gives more quality for some applications, such as live video and phone calls, as it can give high priority for some packets.
- IPv6 also has more security options.
How Client/Server Architecture Works
The client sends a request for a specific web page or a database search, using TCP/IP. The request is broken into HTTP packets to the host computer (for example, a Google server). The
Read MoreData Encapsulation, Addressing, and Switching Techniques
Data Encapsulation Functions
The three primary functions of data encapsulation are:
- Frame Delimiting: Identifies a group of bits that make up a frame, ensuring synchronization between transmitting and receiving nodes.
- Addressing: Each Ethernet header added to the frame contains the physical address (MAC address) that enables a frame to be delivered to a destination node.
- Error Detection: Each Ethernet frame includes a trailer with a cyclic redundancy check (CRC) of the frame contents.
Multicast Address
Read MoreUnderstanding Computer Architecture: MIPS Assembly and Memory
Sign Magnitude
- The leftmost bit (most significant bit) represents the sign:
- 1 – Negative
- 0 – Positive
- 00000101SM = 5
- 10000101SM = -5
Two’s Complement
- Positive numbers are identical to unsigned numbers.
- To negate an unsigned number to its negative:
- Go to the rightmost 1 and flip all bits to the left.
- Example: -610 to (-1) * 01102 to 10102TC
Sign Extension
- If unsigned/2TC is positive, add zeroes to fill out the byte.
- If 2TC is negative, add ones to fill out the byte.
- Generally, add whichever is the leftmost bit