CompTIA A+ Rapid Review: Networking
- Objective 2.1: Identify types of network cables and connectors
- Objective 2.2: Categorize characteristics of connectors and cabling
- Objective 2.3: Explain properties and characteristics of TCP/IP
- Objective 2.4: Explain common TCP and UDP ports, protocols, and their purpose
- Objective 2.5: Compare and contrast wireless networking standards and encryption types
- Objective 2.6: Install, configure, and deploy a SOHO wireless/wired router using appropriate settings
- Objective 2.7: Compare and contrast Internet connection types and features
- Objective 2.8: Identify various types of networks
- Objective 2.9: Compare and contrast network devices and their functions and features
- Objective 2.10: Given a scenario, use appropriate networking tools
This section contains the answers to the “Can you answer these questions?” sections in this chapter.
Objective 2.1: Identify types of network cables and connectors
Fiber cable uses LC, ST, and SC connectors.
RJ-11 connectors are used for phone lines, and RJ-45 connectors are used for networks. Both connectors use twisted-pair cable.
F-type screw-on connectors are used with coaxial cable.
Objective 2.2: Categorize characteristics of connectors and cabling
Fiber supports the longest cables without a repeater. SMF cable supports longer cable runs than MMF cable.
CAT 6 cable supports data transmissions up to 10 Gbps.
RG-6 cable supports both analog and digital transmissions.
Objective 2.3: Explain properties and characteristics of TCP/IP
The IP address 192.168.15.7 is a Class C address. The first number in the IP address 192.168.15.7 is 192, and addresses with the first number between 192 and 223 are Class C addresses.
The IP address FC00::42A:0:0:7F5 is an IPv6 address with leading zeros omitted and using zero compression.
Addresses starting with 169.254 are APIPA addresses, and they are assigned to DHCP clients when a DHCP server has not answered with an available IP address.
DNS provides a mapping for user friendly names (host names) to IP addresses. Clients send the name (such as bing.com) to the DNS server, and the DNS server responds with the IP address.
DHCP provides IP addresses and other TCP/IP configuration information to DHCP clients.
Objective 2.4: Explain common TCP and UDP ports, protocols, and their purpose
Email uses ports 25 (SMTP), 110 (POP3), and 143 (IMAP).
SFTP is encrypted with SSH, and it is used to transfer large encrypted files.
TCP uses a three-way handshake to establish a connection and provides guaranteed delivery.
Objective 2.5: Compare and contrast wireless networking standards and encryption types
Both 802.11a and 802.11n use the 5-GHz frequency range.
802.11n can transmit up to 150 Mbps, 300 Mbps, or 600 Mbps at a time by using multiple antennas. In comparison, 802.11g has a maximum of 54 Mbps.
WEP has been broken and should not be used.
Objective 2.6: Install, configure, and deploy a SOHO wireless/wired router using appropriate settings
You use MAC addresses with MAC address filtering to block network access to specific computers.
Channels 1 and 11 are good alternative channels if channel 6 has excessive interference from other wireless networks.
Internet-facing servers (including gaming servers) should be placed in a DMZ to provide an extra layer of protection.
Objective 2.7: Compare and contrast Internet connection types and features
Fiber and cable broadband connections provide the highest speeds when compared with other wired connections.
Dial-up, DSL, and ISDN connections use phone lines.
Cellular Internet connections are appropriate for people who frequently travel.
Mobile hotspots (also called MiFi) connections are mobile and can be used to provide Internet access for multiple users.
Objective 2.8: Identify various types of networks
A network centered on an individual is a PAN.
A WAN connects two or more networks located in separate geographical locations.
A mesh topology provides the most redundancy.
Objective 2.9: Compare and contrast network devices and their functions and features
Switches provide performance improvements because each device connected to the switch uses a separate segment, resulting in less traffic for each segment. Also, switches provide some security because traffic is not sent to all devices connected to the switch.
Routers used to connect to the Internet commonly include NAT to translate public and private IP addresses. In many cases, the router also includes firewall capabilities.
Modems are used for dial-up Internet connections.
Firewalls block all traffic unless an exception or rule is created to allow the traffic.
Objective 2.10: Given a scenario, use appropriate networking tools
Crimpers are used to connect RJ-45 connectors to twisted-pair cable.
A toner probe is an effective tool used to trace cables.
Loopback plugs are commonly used to test NICs.