Comp TIA Core 1 (Exam 220-1101) Lesson 5: Configuring Network Addressing and Internet Connections
What type of TXT record uses cryptography to help recipient servers reject spoofed messages and spam?
DomainKeys Identified Mail (DKIM).
True or false? A top-level domain such as .com represents the top of the DNS hierarchy.
False. The Domain Name System (DNS) uses root servers at the top of the hierarchy. The root is represented by a trailing dot at the end of a fully qualified domain name (FQDN), though this can very commonly be omitted in ordinary usage.
True or false? A SOHO router uses an embedded modem and Ethernet adapter to forward traffic between public and private network segments over a single hardware port.
False. The modem and Ethernet interfaces use separate ports.
Another technician has scribbled some notes about a firewall configuration. The technician has listed only the port numbers 25 and 3389. What is the purpose of the protocols that use these ports by default?
Port TCP/25 is used by the Simple Mail Transfer Protocol (SMTP) to send and receive email messages. Port TCP/3389 is used by Remote Desktop Protocol (RDP) to connect to a computer's graphical shell over the network.
What feature of DHCP means that it must use UDP at the transport layer?
The Dynamic Host Configuration Protocol (DHCP) uses broadcast addressing, which is not supported by the connection-oriented Transmission Control Protocol (TCP). Consequently, DHCP uses the connectionless User Datagram Protocol (UDP).
True or false? Both 4G and 5G cellular can be used for fixed access broadband as well as in mobile devices.
True. These can work as an alternative to wired broadband or as a backup/failover Internet connection type. Many router models now come with a cellular radio. A subscribed identity module (SIM) card from the service provider must also be installed.
An application uses Transmission Control Protocol (TCP) as it requires data to make it to the destination 100% intact. Which of the following are functions of this protocol? (Select all that apply.) A.Uses SYN/ACK packets. B.Uses TFTP. C.Uses negative acknowledgment. D.Uses FIN.
Uses SYN/ACK packets. Uses negative acknowledgment. Uses FIN. TCP establishes a connection between the sender and recipient using a handshake sequence of SYN, SYN/ACK, and ACK packets. TCP allows the receiver to send a negative acknowledgment (NACK) to force retransmission of a missing or damaged packet. TCP allows the graceful termination of a session using a FIN handshake. The main drawback is that this connection information requires multiple header fields. Network devices typically use Trivial File Transfer Protocol (TFTP) to obtain a configuration file. The application protocol uses its own acknowledgment messaging, so it does not require TCP.
A network technician is checking the records to ensure all the host names match up with the proper IP addresses for the network. What records is the technician checking? (Select all that apply.) A.A B.MX C.FQDN D.AAAA
A AAAA An address (A) record is a resource record that resolves a host name to an IPv4 address. Network technicians can create and update resource records manually (statically). An AAAA record is a resource record on a DNS server that resolves a host name to an IPv6 address. Client and server computers on the network can generate resource records dynamically. A mail exchange (MX) record identifies an email server for the domain so that other servers can send messages to it. A fully qualified domain name (FQDN) is a unique label specified in a DNS hierarchy to identify a particular host within a subdomain within a top-level domain.
You are setting up an ADSL router/modem for a client; unfortunately, the contents of the box have become scattered. What type of cable do you need to locate to connect the router's WAN interface?
Asymmetrical Digital Subscriber Line (DSL) connects to the phone line via a filter. You need an RJ11-terminated patch cord to make the connection.
A network technician must allow employee computers to securely connect to the corporate network from alternate locations. What is the best method for the technician to use? A.DMARC B.DHCP scope C.VPN D.VLAN
C.VPN A virtual private network (VPN) enables hosts to connect to the LAN from locations other than the site by connecting to the local network via a secure remote access server. The Domain-Based Message Authentication, Reporting, and Conformance (DMARC) framework ensures that Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) are effective. A Dynamic Host Configuration Protocol (DHCP) scope is the range of addresses that a DHCP server can offer to client hosts in a particular subnet. A virtual LAN (VLAN) is a logical network segment comprising a broadcast domain established using a feature of managed switches to assign each port a VLAN ID.
A networking student is learning about IP addressing and discovers which of the following facts are NOT true regarding IPv6? A.Divided into two main parts. B.Will replace IPv4. C.Expressed in hexadecimal notation. D.Expressed in dotted decimal notation.
Expressed in dotted decimal notation. To make IPv4 addresses easier to use, they are in dotted decimal notation. IPv6 addresses are in hexadecimal notation. An IPv6 address divides into two main parts: the first 64 bits designate the network ID, while the second 64 bits designate a specific interface. The pool of available IPv4 public addresses is not very large, compared to the number of devices that need to connect to the internet, so IP version 6 (IPv6) will replace IPv4 completely. IPv6 addresses are in hexadecimal notation. To express a 128-bit IPv6 address in hex, the binary address divides into eight double-byte (16-bit) values delimited by colons.
A company hires a network technician who is reviewing the network setup documentation. The technician sees that the company has fiber optic cable running all the way up to the building. This represents what type of connection? A.FTTC B.VDSL C.ONT D.FTTP
FTTP A fiber to the premises (FTTP) internet connection means that the service provider's fiber optic cable runs all the way to the customer's building. A fiber to the curb (FTTC) solution retains some sort of copper wiring to the customer premises while extending the fiber link to a communications cabinet servicing multiple subscribers. The service providers with their roots in telephone networks use very high-speed DSL (VDSL) to support FTTC. VDSL achieves higher bit rates than other DSL types at the expense of range. An optical network terminal (ONT) is a device that converts between optical and electrical signaling deployed to facilitate full fiber internet connection types.
True or false? At the Transport layer, connections between hosts to exchange application data are established over a single port number.
False. The server application is identified by one port, but the client must also assign its own port to track the connection.
A technician is sent to the personal office space of the organizations board to set up a SOHO environment for the executive. While preparing for the home installation, the technician creates a list of items that will be needed to successfully setup and configure the SOHO network. What is the function of using a switch in a SOHO environment? A.It connects to the service provider cabling and transfers frames over the link B.It allows local computers and other host types to connect to the network via RJ-45 ports C.It forwards packets over the WAN interface if a location destination IP address is not available D.It allows hosts to connect to the network over Wi-Fi
It allows local computers and other host types to connect to the network via RJ-45 ports When setting up and configuring a SOHO Network, a switch allows local computers and other host types to connect to the network via RJ-45 ports. This will be an unmanaged switch, so no configuration is necessary. A modem, versus a switch, connects to the service provider cabling and transfers frames over the link. The modem type must be matched to the network type (ADSL, VDSL, or cable). Routers, and not switches, forward packets over the WAN (Internet) interface if they do not have a local destination IP address. An access point allows hosts to connect to the network over Wi-Fi.
The technician has made a note to check that port 445 is blocked by the firewall. What is the purpose of the protocol that uses this port by default, and why should it be blocked?
Port TCP/445 is used by the Server Message Block (SMB) protocol that implements Windows File/Printer Sharing. SMB is designed for use on local networks only. Allowing access from the Internet would be a security risk.
A network technician is purchasing a digital subscriber line (DSL) service for a business that transfers large amounts of data back and forth between branches. What is the best connection type for the business? ADSL ISP PSTN Symmetric DSL
Symmetric DSL Symmetric versions of DSL offer the same uplink and downlink speeds and are of more use to businesses and for branch office links, where more data passes upstream than with normal internet use. Asymmetrical DSL (ADSL) provides a fast downlink but a slow uplink, with the latest (ADSL2+) offering downlink rates up to about 24 Mbps and uplink rates of 1.25 Mbps or 2.5 Mbps. Internet service providers (ISPs) establish high-speed links between their networks, using transit and peering arrangements to carry traffic to and from parts of the internet they do not physically own. The public switched telephone network (PSTN) is the national and global telecommunications network that has fiber optic cabling at its core.
An application developer wants to ensure packets arrive at the destination in the correct order and none are lost when an application communicates across the network. Which protocol will the application developer use? A.UDP B.TCP C.IP D.DNS
The Transmission Control Protocol (TCP) can identify and recover from lost or out-of-order packets. Failing to receive a packet or processing it incorrectly can cause serious data errors. The User Datagram Protocol (UDP) is faster than TCP and comes with less of a transmission overhead because it does not need to send extra information to establish reliable connections. The Internet Protocol (IP) provides packet addressing and routing within a network of networks. For data to travel from one IP network to another, an intermediate system must forward it. The Domain Name System (DNS) is a service that maps fully qualified domain name labels to IP addresses on most TCP/IP networks, including the internet.
A network technician is setting static IPv4 addresses on servers. Which settings would be considered optional for ensuring proper communications within a local area network? (Select all that apply.) A.The gateway B.The alternate DNS C.IP address D.Subnet mask
The gateway The alternate DNS The gateway parameter is the IPv4 address of a router and is the IP address to which packets destined for a remote network should go by default. This will be changed for groups of locally connected devices. The Domain Name System (DNS) and alternate DNS servers provide resolution of host and domain names to their IP addresses. While the primary DNS may be essential for locating resources on the internet, an alternate is optional. Each host must be configured with an IP address and subnet mask at a minimum to communicate on an IPv4 network. The subnet mask is entered in dotted decimal notation, such as 255.255.255.0. When used with the IP address 192.168.0.100 , this mask identifies 192.168.0.0 as the network ID and means that the last octet ( .100 ) is the host ID.
You need to ensure that a print device receives the same IP address when connecting to the network. What value do you need to configure on the DHCP server to enable a reservation?
The reservation should be configured with the media access control (MAC) address of the print device (plus the IP address to assign).
You are advising another technician about typical DNS configuration. The technician thinks that the name server hosting the 515 support domain resource records on the Internet should be configured as the primary DNS server entry in the IP configuration of local clients. Why is this unlikely to be the case?
The role of a name server is to respond to queries for the resource records of the specific domain(s) that it is responsible for. The role of the DNS server types listed in a client's IP configuration is to resolve requests for records in any valid domain. To do this, the resolver must take on the task of querying multiple name servers on behalf of the client. Mixing these roles on the same server machine is possible in theory, but for performance and security reasons, they are more commonly performed by separate servers.
A network technician is configuring hosts to request IP configuration from a server. What protocol is the technician configuring? A.HTTPS B.SSH C.DHCP D.TFTP
The technician is configuring Dynamic Host Configuration Protocol (DHCP) which is a protocol used by clients to request IP configuration information from a server. HyperText Transfer Protocol Secure (HTTPS) is a protocol used to deliver web pages and other resources. It uses encryption to authenticate the server and protect the information. Secure shell (SSH) is a protocol that accesses the command-line interface of a computer from across the network and uses encryption to authenticate the server and user and protect the information. Network devices typically use Trivial File Transfer Protocol (TFTP) to obtain a configuration file. The application protocol uses its own acknowledgment messaging, so it does not require TCP.
Which network configuration technology can be configured on switches to divide a local network into multiple broadcast domain segments?
Virtual LAN (VLAN).
What type of value would you expect a query for an AAAA resource record to return?
An IPv6 address.
You are assisting another customer with a full fiber connection terminated to an optical network terminal (ONT). The customer's router was disconnected while some building work was being completed, and the patch cable is now missing. The customer thinks that the cable should be a fiber optic one because the service is "full fiber." What type of cable do you need to locate?
An RJ45 unshielded twisted pair (UTP) patch cable. The ONT converts the optical signal over the external fiber optic cable to an electrical one to connect to the local router.
