Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CompTIA A+ 1101 (Core 1) > 2.6 Compare & contrast common network configuratoin concepts > Flashcards

2.6 Compare & contrast common network configuratoin concepts Flashcards

1
Q

What is a DHCP scope?

A

DHCP server’s address range for client hosts in a subnet

A scope of 192.168.0.100 - 192.168.0.199 allows for 100 dynamically addressed hosts on the LAN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What addresses should the DHCP scope exclude?

A

Addresses that have been configured statically

i.e. if you’ve manually assigned the IP address 192.168.1.10 to a printer, you would want to exclude this address from the DHCP scope to prevent the DHCP server from assigning it to another device.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How is a host configured to use DHCP?

A

By setting its TCP/IP config. to automatically obtain an IP address

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens when a DHCP client connects to a network?

A

It broadcasts a DHCPDISCOVER packet to find a DHCP server

Since clients BROADCAST this packet, meaning they send it to all devices on the network, they do not need to know the DHCP server’s IP address

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why do DHCP servers need to have a static IP address?

A

To ensure DHCP clients reliably find the server for IP address assignment or renewal

If the DHCP server’s IP address were to change frequently, DHCP clients wouldn’t be able to reliably locate it to obtain network configuration information.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the DHCP server do when it receives a DHCPDISCOVER packet?

A

Responds with a DHCPOFFER packet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a DHCPOFFER packet contain?

A

Address & other configuration data

other config data like the default gateway & DNS server addresses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the DHCP client do when it receives a DHCPOFFER packet?

A

Broadcasts a DHCPREQUEST onto the network

it broadcasts the packet to inform all DHCP servers on the network that the client has accespted the IP address offer provided by one of the servers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens after a DHCPREQUEST packet is broacasted onto the network?

A

Server responds with a DHCPACK packet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens when the client receives a DHCPACK packet?

A

Client broadcasts an ARP message to check that the address is unused

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Meaning of ARP?

A

Address Resolution Protocol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What if the client detects an IP address is already used after sending an ARP message?

A

It declines the IP address offer & requests a new one

If it detects that it isnt used, then it proceeds to use it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can a client do to retain an IP address before the lease ends?

A

Attempt to renew or rebind the lease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What if a client can’t renew/rebind its IP address lease?

A

Must release the IP address & start the discovery process again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can a client’s network configuration be changed?

i.e. assiging different IP addresses or adjusting other settings

A

via DHCP server

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When do client network changes take effect after updating via DHCP server?

A

When DHCP client seeks a new lease

A new lease can also be requested manually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens in a DHCP reservation?

A

DHCP server reserves an IP address for a device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does DHCP server know which device to assign the reserved address to?

A

Being configured with a list of MAC addresses of hosts for IP address assignment

When contacted by a listed host, it issues a lease for reserved IP

Some OSs send a different unique identifier instead of MAC addresses by default. Configuring the identification method ensures accurate server info.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a hostname?

A

Label assigned to a device on a network

It serves as a human-readable identifier for the device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is the possibility of duplicate hostnames on the Internet avoided?

A

Having the hostname combined with a domain name & suffix

Note that, while combining the hostname with a domain name and suffix helps, it’s part of a broader set of measures used to avoid duplicate hostnames on the Internet. (i.e. Domain registration, Reverse DNS lookup, etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Meaning of FQDN?

A

Fully Qualified Domain Name

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a FQDN?

A

Hostname combined with a domain name & suffix

i.e. nut.widget.examplle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Identify hostname of this FQDN:

nut.widget.example

A

nut

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Identify domain name of this FQDN:

nut.widget.example

A

widget

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Identify the TLD (domain suffix) of this FQDN:

nut.widget.example

A

.example

A domain suffix could also contain subdomains between the host & domain name

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Meaning of TLD?

A

Top-Level Domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How are FQDNs assigned & managed?

A

Using DNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is DNS?

A

Global hierarchy of distributed name server databases containing domain and host info.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is at the top of the DNS hierarchy?

A

Root

Root is represented by a null label, consisting of just a (.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How many root servers does the DNS hierarchy have?

A

13 root-level servers

(A to M)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is below the root in the DNS hierarchy?

A

TLDs

The most prevalent are genereic (i.e. .com, .org, .net, .info, .biz), sponsored (i.e. .gov, .edu), & country code (i.e. .uk, .ca, .de)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is DNS operated by?

A

ICANN

ICANN also manages genereic TLDs. Country codes are generally managed by an org. appointed by the relevant government

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does a client need for hostname/FQDN to IP resolution?

A

The appropriate record from a DNS server

34
Q

What must at least one DNS server be configured as in a network infrastructure?

A

Configured to act as an authoritative store of information about each domain

This means that there should be at least one DNS server configured to hold the official DNS records for each domain in that network

35
Q

What do authoritative DNS servers contain?

A

Numerous resource records

36
Q

What do DNS resource records allow the name server to do?

A

Resolve domain name & services into IP addresses

37
Q

What is an Address record (A) used for?

A

Resolving a host name to an IPv4 address

38
Q

What is an AAAA record used for?

A

Resolving a host name to an IPv6 address

39
Q

Meaning of MX?

A

Mail eXchanger

40
Q

What are MX records used for?

A

Identify the domain’s email server so other servers can send messeges to it

41
Q

Why assign preference values to MX records in networks with multiple email servers?

A

To indicate priority order for handling incoming email

The lower the priority number, the higher the priority

42
Q

What does the host name with an MX record need?

A

Associated A or AAAA record

43
Q

What are TXT records used for?

A

Storing free-form text used to support other networks services

44
Q

2 main reasons domain names have TXT records?

A

To verify email services & block spam

Spam is spoofed & unwatned messages

45
Q

Meaning of SPF?

A

Sender Policy Framework

46
Q

How is SPF record implemented as?

A

TXT resource record in DNS

47
Q

How many SPF records should each domain have?

A

1

48
Q

What does SPF identify?

A

Email servers that are allowed to send emails on behalf of a domain

49
Q

What does SPF do?

A
  • Identifies authorized hosts
  • Handles unauthorized servers
50
Q

What does it mean that SPF identifies authorized hosts?

A

identifies email servers that are authorized to send emails on behalf of a domain

SPF checks if the sending mail server is authorized to send emails on behalf of a domain by querying the domain’s DNS records. For instance, if an email claims to be from “example.com,” the receiving mail server checks “example.com”’s SPF record. If the sending server’s IP is listed, the email passes authentication; if not, it fails, potentially indicating fraud. SPF helps prevent email spoofing and phishing by confirming the sending server’s legitimacy through DNS records.

51
Q

3 things SPF can do to emails from servers not on the list?

A
  • Accept
  • Flag
  • Reject
52
Q

Syntax used in SPF to accept emails from servers not listed?

A

+all

53
Q

Syntax used in SPF to flag emails from servers not listed?

A

~all

54
Q

Syntax used in SPF to reject emails from servers not listed?

A

-all

55
Q

Meaning of DKIM?

A

DomainKeys Identified Mail

56
Q

3 DNS spam management records?

A
  • SPF
  • DKIM
  • DMARC

These are TXT records

57
Q

What does DKIM do?

A

Uses cryptography to validate the source server for a given email

The sender’s server creates a unique digital signature by hashing specific email content and encrypting it with the sender’s private key. The recipient’s server then retrieves and verifies the DKIM signature using the sender’s public key from DNS records. If successful, it confirms the email’s origin and integrity; otherwise, it flags potential tampering for further review.

58
Q

Does DKIM replace or supplement SPF?

A

Either or

It can do either one

59
Q

How is DKIM configured?

A

Org. uploads a public encryption key as a TXT record in the DNS server

Orgs. receiving messages can use this key to verify that a message derives from an authentic server

60
Q

Meaning of DMARC?

A

Domain-based Message Authentication, Reporting, & Conformance

61
Q

What does DMARC framework do?

A

Ensures SPF & DKIM are being utilized effectively

62
Q

How are DMARC policies published as?

A

DNS TXT record

63
Q

Which DNS spam management records can DAMRC use?

A

SPF or DKIM or both

64
Q

What does DMARC allow?

A
  • Senders to define how DMARC authentication failures are treated
  • Recipients to report DMARC authentication failures to the sender
65
Q

3 ways DMARC authentication failures can be treated?

A
  • Flag
  • Quarantine
  • Reject
66
Q

What type of switches support VLANs?

A

Managed switches

67
Q

Meaning of VLAN?

A

Virtual LAN

68
Q

What does VLAN do to managed switches?

A

Divides the ports into groups

69
Q

Simplest way of assigning a node to a VLAN?

A

Configure switch port with a VLAN ID of 2-4049

i.e. Switch ports 1-10 could be VLAN 10, and ports 11-20 VLAN 20. Host A on port 2 is in VLAN 10, and host B on port 12 is in VLAN 20.

70
Q

What is VLAN ID 1 referred to?

A

default VLAN

71
Q

What VLAN ID do ports on a managed switch default to?

A

VLAN ID 1

Unless configured differently

72
Q

What happens when hosts are placed in separate VLANs?

A

They can’t directly communicate with each other

Even though they are on the same managed switch

73
Q

What must each VLAN be configured with?

A

Its own subnet address & IP address range

74
Q

How are communications between VLANs done?

A

Via IP router

Each VLAN must also be provisioned with its own DHCP & DNS services

75
Q

Benefits of VLAN?

A
  • Reduces impact of excessive broadcast traffic
  • Traffic is more easily filtered & monitored

VLANs are also used to separate nodes by traffic type, like isolating VoIP devices for easier prioritization over other VLANs.

76
Q

Meaning of VPN?

A

Virtual Private Network

77
Q

What do VPNs do?

A

Allows hosts to remotely connect to the LAN

78
Q

How does a host connect to a LAN with a VPN?

A

Via a remote access server that accepts connections from the Internet

Because the Internet is a public network, ensure the VPN connection is secure

79
Q

What do secure VPNs configure?

A

A protected tunnel through the Internet

It employs specialized connection protocols and encryption to safeguard the tunnel from snooping and ensure proper user authentication.

80
Q

Another way VPNs can be used?

A

Securely connect sites over public or local networks for added security

A company securely links its branch offices over the internet using VPNs. This allows employees to access shared resources as if they were on the same local network, while encryption ensures data security during transmission.

CompTIA A+ 1101 (Core 1) (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions