COMPTIA 1101 section 2 notes

What is the port number for FTP data and control?

FTP uses TCP port 20 for data and TCP port 21 for control.

What is the port number for SSH?

SSH uses TCP port 22.

What is the port number for Telnet?

Telnet uses TCP port 23.

What is the port number for SMTP?

SMTP uses TCP port 25.

What port does DNS use?

DNS uses UDP port 53.

What ports does DHCP use?

DHCP uses UDP ports 67 and 68.

What is the port number for HTTP and HTTPS?

HTTP uses TCP port 80, HTTPS uses TCP port 443.

What port does POP3 use?

POP3 uses TCP port 110.

What port does IMAP use?

IMAP uses TCP port 143.

What ports does SMB use?

UDP 137, TCP 139, and TCP 445.

What ports does SNMP use?

SNMP uses UDP 161 for queries and UDP 162 for traps.

What is the port number for LDAP?

LDAP uses TCP port 389.

What is the port number for RDP?

RDP uses TCP port 3389.

What is the port number for AFP (Apple Filing Protocol)?

AFP uses TCP port 548.

What is the port number for AFP/SLP (Service Location Protocol)?

AFP/SLP uses TCP/UDP port 427.

What does a router do?

Routes traffic between IP subnets and makes forwarding decisions based on IP addresses.

What is the difference between managed and unmanaged switches?

Managed switches support VLANs, STP, and SNMP; unmanaged switches are plug-and-play.

What is the function of an access point?

Extends a wired network to wireless devices, forwards based on MAC addresses.

What is PoE and where is it used?

Power over Ethernet supplies power and data over one cable, used for phones, cameras, APs.

What frequency and speed does 802.11a use?

5 GHz, up to 54 Mbps.

What frequency and speed does 802.11b use?

2.4 GHz, up to 11 Mbps.

What is the speed of 802.11g?

54 Mbps at 2.4 GHz.

What are the features of 802.11n?

Dual-band (2.4/5 GHz), MIMO, up to 600 Mbps.

What are the advantages of 802.11ac?

5 GHz, MU-MIMO, channel bonding, up to ~7 Gbps.

What is OFDMA used in 802.11ax (Wi-Fi 6)?

Efficient channel allocation in high-density environments.

What does a DHCP server do?

Automatically assigns IP addresses and other network settings.

What does a DNS server do?

Resolves domain names to IP addresses.

What is a proxy server used for?

Acts as an intermediary for requests, offers caching and filtering.

What is the function of a load balancer?

Distributes network traffic across multiple servers.

What is a default gateway?

A router IP that connects the device to networks outside the local subnet.

What is APIPA?

Automatic IP assignment in 169.254.0.0/16 when no DHCP is available.

What is DORA in DHCP?

Discover, Offer, Request, Acknowledge - the 4-step DHCP IP assignment process.

What is an A record in DNS?

Maps a hostname to an IPv4 address.

What is an AAAA record?

Maps a hostname to an IPv6 address.

What is an MX record?

Specifies the mail server responsible for receiving emails.

What is SPF used for?

Defines which servers can send mail on behalf of a domain.

What does DKIM do?

Digitally signs outgoing email to validate domain ownership.

What is DMARC?

Tells receiving servers how to handle failed SPF/DKIM validations.

What is the main drawback of satellite internet?

High latency (~500 ms round trip).

What is DOCSIS used for?

Data Over Cable Service Interface Specification for cable internet.

What is the benefit of fiber?

High-speed and long-distance data transmission.

What is a WISP?

Wireless Internet Service Provider - often used in rural areas.

What is a cable crimper used for?

Attaches connectors (e.g., RJ-45) to the end of a cable by 'crimping' it securely.

What does a punch-down tool do?

Inserts and trims wires into a wiring block like a 66 or 110 block.

What is the purpose of a cable tester?

Checks continuity and pin configuration of network cables to detect broken or miswired pairs.

What does a tone generator and probe do?

Sends a signal through a wire which can be traced with the probe to locate cables in walls or bundles.

What is a loopback plug used for?

Tests the functionality of network ports by looping traffic back into the port.

What is a WiFi analyzer used for?

Identifies signal strength, interference, and wireless network configurations.

What is a port mirror (SPAN)?

Copies traffic from one switch port to another for monitoring or packet capture.

What is a network tap?

Physically splits network traffic to send a copy to a monitoring system.