2.6 Compare and contrast common network configuration concepts.

Question 1

DNS Address A

Answer 1

A records are for IPv4 addresses– Modify the A record to change the host name to IP address resolution.

Question 2

DNS Address AAAA

Answer 2

AAAA records are for IPv6 addresses– The same DNS server, different records.

Question 3

Mail Exchanger

Answer 3

Determines the host name for the mail server - this isn’t an IP address; it’s a name. (See pic on notes).

Question 4

Text records (TXT).

Answer 4

Human-readable text information–Useful public information
–Was originally designed for informal information. Can be used for verification purposes–If you have access to the DNS, then you must be the administrator
of the domain name. Commonly used for email security
–External email servers validate information from your DNS. (See pic on notes).

Question 5

Domain Keys Identified Mail (DKIM) (See pic on slide)

Answer 5

Digitally sign a domain’s outgoing mail
–Validated by mail servers, not usually
seen by the end user–The public key is in the DKIM TXT record.

Question 6

Sender Policy Framework (SPF) (See pic on slide).

Answer 6

SPF protocol–A list of all servers authorized to send emails
for this domain–Prevent mail spoofing –Mail servers perform a check to see if incoming mail really did come from an authorized host.

Question 7

Domain-based Message Authentication,
Reporting, and Conformance (DMARC) (See pic on slide)

Answer 7

Domain-based Message Authentication, Reporting,
and Conformance (DMARC) –Prevent unauthorized email use (spoofing) –An extension of SPF and DKIM.
You decide what external email servers should do with
emails that don’t validate through SPF or DKIM.That policy is written into a DMARC TXT record–Accept all, send to spam, or reject the email–Compliance reports can be sent to the email administrator.

Question 8

DHCP Leases

Answer 8

Leasing your address– It’s only temporary– But it can seem permanent.
* Allocation– Assigned a lease time by the DHCP server– Administratively configured.
* Reallocation– Reboot your computer– Confirms the lease.
* Workstation can also manually release the IP address.

Question 9

DHCP Scope properties

Answer 9

IP address range and excluded addresses. Subnet mask, Lease durations. Other scope options, DNS server, Default gateway, VOIP servers.

Question 10

DHCP address reservation

Answer 10

Administratively configured.

Question 11

Virtual LANs (See slide_

Answer 11

Virtual Local Area Networks
* A group of devices in the same broadcast domain
* Separated logically instead of physically

Question 12

Virtual private network (VPN) (See slide)

Answer 12

Encrypted (private) data traversing a public network.
* Concentrator– Encryption/decryption access device, often integrated into a firewall.
* Many deployment options, Specialized cryptographic hardware, Software-based options available.