Module 4 Glossary

Christian Igbaras — Thu, 04 May 2023 20:22:01 +0000

New terms and their definitions: Course 2 Week 4

A record: The most common resource record, used to point a certain domain name at a certain IPv4 IP address
Anycast: A technique that's used to route traffic to different destinations depending on factors like location, congestion, or link health
Automatic allocation: A range of IP addresses is set aside for assignment purposes
Caching and recursive name servers: They are generally provided by an ISP or your local network, and their purpose is to store domain name lookups for a certain amount of time
CNAME: A resource record used to map one domain to another
DHCP discovery: The process by which a client configured to use DHCP attempts to get network configuration information
Domain Name System (DNS): A global and highly distributed network service that resolves strings of letters, such as a website name, into an IP address
DNS zones: A portion of space in the Domain Name System (DNS) that is controlled by an authoritative name server
Domain: Used to demarcate where control moves from a top-level domain name server to an authoritative name server
Domain name: A website name; the part of the URL following www.
Dynamic allocation: A range of IP addresses is set aside for client devices and one of these IPs is issued to these devices when they request one
Fixed allocation: Requires a manually specified list of MAC address and the corresponding IPs
Fully qualified domain name: When you combine all the parts of a domain together
IP masquerading: The NAT obscures the sender's IP address from the receiver
MX record: It stands for mail exchange and this resource record is used in order to deliver email to the correct server
Name resolution: This process of using DNS to turn a domain name into an IP address
Network Address Translation (NAT): A mitigation tool that lets organizations use one public IP address and many private IP addresses within the network
NS record: It indicates other name servers that may also be responsible for a particular zone
NTP servers: Used to keep all computers on a network synchronized in time
Pointer resource record: It resolves an IP to a name
Port forwarding: A technique where specific destination ports can be configured to always be delivered to specific nodes
Port preservation: A technique where the source port chosen by a client, is the same port used by the router
Proxy service: A server that acts on behalf of a client in order to access another service
Quad A (AAAA) record: It is very similar to an A record except that it returns in IPv6 address instead of an IPv4 address
Recursive name servers: Servers that perform full DNS resolution requests
Reverse lookup zone files: They let DNS resolvers ask for an IP, and get the FQDN associated with it returned
Reverse proxy: A service that might appear to be a single server to external clients, but actually represents many servers living behind it
Round robin: It is a concept that involves iterating over a list of items one by one in an orderly fashion
SRV record: A service record used to define the location of various specific services
Start of authority: A declaration of the zone and the name of the name server that is authoritative for it
Top Level Domain (TLD): The top level of the DNS or the last part of a domain name. For example, the “com” in www.weather.com
Time-To-Live field (TTL): An 8-bit field that indicates how many router hops a datagram can traverse before it's thrown away
Two-factor authentication: A technique where more than just a username and password are required to authenticate. Usually, a short-lived numerical token is generated by the user through a specialized piece of hardware or software
TXT record: It stands for text and was originally intended to be used only for associating some descriptive text with a domain name for human consumption
Types of DNS servers: There are five primary types of DNS servers; caching name servers, recursive name servers, root name servers, TLD name servers, and authoritative name servers
Virtual Private Network (VPN): A technology that allows for the extension of a private or local network, to a host that might not work on that same local network
Zone Files: Simple configuration files that declare all resource records for a particular zone

VPNs: Legal or Illegal?

Christian Igbaras — Thu, 04 May 2023 20:14:15 +0000

VPN’s main task is to add an extra layer of privacy and security to online activities. VPNs can be used in a variety of ways:

Governments and corporations use VPNs to secure their workplace

VPNs can help secure personal data while using public WiFi

VPN s can conceal illegal activity, such as stealing copyrighted material

Because some, unfortunately, do use VPNs for illegal matters, some countries have made the use of VPNs illegal. Other countries allow the use VPNs if no illegal activity is being done while using one.

TCP ports and sockets

Christian Igbaras — Tue, 02 May 2023 23:12:08 +0000

Network services are run by listening to specific ports for incoming data requests.

Ports are represented by a single 16-bit number (65535 different port ids)
Ports are split up by the IANA (Internet Assigned Numbers Authority) into three categories: System Ports (ports 1-1023), User Ports (ports 1024-49151), and Ephemeral (Dynamic) Ports (ports 59152-65535).
A socket is a port that a TCP segment has activated to listen for data requests.
Ports allow services to send data to your computer but can also send malware into a client program. It's important to secure your ports

DEV Community: Christian Igbaras

Module 4 Glossary

VPNs: Legal or Illegal?

TCP ports and sockets