New CompTIA unit 6 study guide

DHCP Reservation

A permanent IP assignment for a specific device that ensures always-on functionality while maintaining centralized management

DHCPDISCOVER

The first step in the DHCP lease process where a client broadcasts to find available servers

DHCP Server

The device used to automatically configure workstations with IP addresses, subnet masks, and default gateways

ARP Message

A broadcast sent by a client to ensure an offered IP address is not already in use by another device

T1 Timer

The timer that signals when a DHCP client should start attempting to renew its current lease

Long Lease Time

A setting that causes the DHCP server's available pool of IP addresses to be replenished less frequently

Default Gateway Option

The DHCP option that specifies the IP address of the router for the client

DHCP Scope

A range of IP addresses and options configured for a single subnet on a DHCP server

DHCP Relay

A service that allows a router to forward DHCP traffic between different subnets to reach a server

Socket

A unique identifier for a network connection, consisting of an IP address and a port number

Port Numbers

Identifiers used in conjunction with IP addresses to direct packets to specific services or applications

TCP Connection ID

A connection uniquely identified by the combination of source/destination IP addresses and source/destination port numbers

Transport Layer

The OSI layer where TCP (Transmission Control Protocol) operates

TCP Segments

The unit of data used by TCP to divide information from the Application layer

Netstat

A command-line tool used to check the state of ports and active network connections on a computer

SYN Flag

The TCP flag set by a client to initiate the three-way handshake

FIN Flag

The TCP flag used by both client and server to indicate they want to gracefully close a connection

RST Flag

A TCP flag sent to abruptly end a session or indicate a connection error

UDP

A protocol suitable for applications sending small amounts of data that do not require acknowledgment

DHCP Ports

UDP 67 (Server) and UDP 68 (Client)

Email Ports

TCP 25 (SMTP) and TCP 143 (IMAP)

NTP Port

UDP 123, used for network time synchronization

SLAAC

An IPv6 autoconfiguration method allowing a host to generate its own link-local address and verify uniqueness

Router Advertisements

IPv6 messages that inform hosts of network prefixes and autoconfiguration options

VLAN

A subnetwork created by configuring switch ports into a broadcast domain based on logical groups

Static NAT

A NAT implementation that maps a single private IP address to a single public IP address

PAT

Port Address Translation

it maps multiple private IP addresses to a single public IP address using different ports

Longest Prefix Match

The rule used by routers to select a route when multiple matches exist in the routing table

A Record

A DNS record used to resolve a host name to an IPv4 address

AAAA Record

A DNS record used to resolve a host name to an IPv6 address

MX Record

A DNS record that identifies email servers and requires an associated A or AAAA record to function

Secondary DNS Server

A server that holds a read-only copy of a DNS zone for redundancy

Round Robin DNS

A method used to distribute network traffic across multiple servers

FQDN

Fully Qualified Domain Name

consists of the hostname plus the full domain path (e.g., https://www.google.com/search?q=host.example.com)

Dig

A primary command-line tool used specifically to query DNS servers for information

TLS Handshake

The process where a server provides its digital certificate to a client for authentication and encryption negotiation

Access Layer

The layer in a three-tiered hierarchy responsible for connecting end-user devices to the network

Core Layer

The layer responsible for providing fault-tolerant, high-speed interconnections between different network blocks