2.4 Common Network Config. Concepts

Scope

a range of IP addresses that a DHCP server can hand out

Reservation

Ensures that a specific computer or device identified by its MAC address will always be given the same IP address

• only given to special devices like network printers, servers, routers, etc…

• Static IP

Lease

The amount of time an IP address is assigned to a computer

• renewal is typically done automatically by DHCP server

Exclusion

IP addresses that are reserved for devices that use them as static IP addresses

• Dynamic IP

Mail Exchange (MX) Record

Points the server where mail should be delivered for that domain name

Domain-based Message Authentication Reporting and Conformance (DMARC)

Directs receiving mail servers how to validate the sender of an email

• protects organization’s domain against phishing & spoofing

Virtual Private Network (VPN)

Establishes a secure/reliable network over an insecure connection like the internet

• disguises your identity by hiding your IP address

• encrypts and protects your internet data by encapsulating the data with an extra layer or protection (tunneling)

Virtual Local Area Network (VLAN)

LAN where the computers, servers, and other network devices are logically connected regardless of their physical location

Top Level Domain (TLD)

Responsible for information of top level domains as:

• .com, .net, .org

A Record

resolves domain name to IPv4 address

AAAA Record

resolves domain name to IPv6 address

Canonical (CNAME) Record

Resolves a domain or subdomain to another domain name

• computers read domain names from right to left

TXT Record

Contains miscellaneous information about a domain

• also used to prevent email spam

• makes sure incoming mail is coming from a verified authorized source

Domain Keys Identified Mail (DKIM)

used to prevent email spoofing

• adds a cryptographic signature to emails

Sender Policy Framework (SPF)

• used to prevent email spoofing

• allows the owner of a domain to publish a list of authorized IP addresses & servers that are allowed to send emails on their behalf