Missed questions

nmap -sn

Performs host discovery only (ping scan), identifying live hosts without executing a port scan.

nmap -sT

Performs a TCP connect scan by establishing a full TCP connection to identify open ports.

nmap -sU

Performs a UDP scan to discover open UDP ports.

nmap -p

Specifies target ports or port ranges to scan (e.g., nmap -p 22,80 192.168.1.10).

802.11r

Fast BSS Transition standard that speeds up roaming between access points by reducing authentication delays.

802.11k

Radio Resource Management standard that helps clients discover neighboring access points to inform roaming decisions.

802.11v

Wireless Network Management standard that allows the network to provide roaming recommendations and data to clients.

Channel bonding

Technique of combining adjacent wireless channels to increase available bandwidth (e.g., in 802.11n within the $5\,GHz$ band).

nmap -sn

Performs host discovery only (ping scan), identifying live hosts without executing a port scan.

nmap -sT

Performs a TCP connect scan by establishing a full TCP connection to identify open ports.

nmap -sU

Performs a UDP scan to discover open UDP ports.

nmap -p

Specifies target ports or port ranges to scan (e.g., nmap -p 22,80 192.168.1.10).

802.11r

Fast BSS Transition standard that speeds up roaming between access points by reducing authentication delays.

802.11k

Radio Resource Management standard that helps clients discover neighboring access points to inform roaming decisions.

802.11v

Wireless Network Management standard that allows the network to provide roaming recommendations and data to clients.

Channel bonding

Technique of combining adjacent wireless channels to increase available bandwidth (e.g., in 802.11n within the $5\,GHz$ band).

SPF and DKIM

Email authentication mechanisms whose configuration data and public keys are published in DNS TXT records.

DNSSEC

Extension that authenticates DNS data using digital signatures to verify response integrity and data origin.

DNS over HTTPS (DoH)

Protocol that transports DNS queries over HTTPS to provide encryption and privacy in transit.

Screened subnet (DMZ)

Network design that isolates public-facing services (e.g., web servers) from protected internal networks (e.g., database servers).

Recovery Point Objective (RPO)

The maximum acceptable amount of data loss resulting from a disruption, expressed as a time interval.

Router-on-a-stick

Topology using a single physical router interface with VLAN subinterfaces (e.g., interface G0.30 using encapsulation dot1Q 30) for inter-VLAN routing.

Directly connected route

A routing table entry automatically created for a network attached to an active router interface.

Default route

A route used when no specific route matches the destination IP, usually pointing to an upstream gateway.

QSFP+

Transceiver standard supporting $40\,GbE$ using four $10\,Gbps$ lanes.

Solid amber switch LED

Port status light indicating a port blocked by Spanning Tree Protocol (STP).

tel: URI in SIP

A URI format in Session Initiation Protocol used to identify a telephone number for dialing.

Multicast MAC address (IPv4)

Ethernet destination address starting with 01:00:5E used to deliver traffic to a group of devices.

Application Programming Interface (API)

A set of protocols for software interaction, allowing tasks like adding firewall rules via requests to an endpoint.

Line protocol down

Interface state where the physical link is up but Layer 2 logical communication is down, often caused by encapsulation mismatches.