Section 1.6 Flashcards
How many dns root server clusters are there?
13
TLD
Top Level Domain
What are examples of some Top Level Domains?
.com
.net
.org
.gov
.edu
.(country)
FQDN
Fully Qualified Domain Name
What is a Fully Qualified Domain Name?
An FQDN has the subdomain/hostname, domain and top level domain.
What is the process of DNS resolution?
First, the computer checks its local cache. If not there, then the cache of the DNS resolver like the ISP or Google. If not there, then the TLD server.
What’s the difference between a non-authoritative answer vs an authoritative answer in a DNS lookup?
Non-authoritative is cached information, whereas authoritative is directly from the source.
What term determines how often the DNS cache is updated?
The Time To Live or TTL
In what increments of time is the domain TTL in?
number of seconds
Command for simple forward and reverse dns lookup
nslookup [domain/IP]
Command for detailed foward dns lookup
dig [domain]
Command for detailed reverse dns lookup
dig -x [IP]
NTP
Network Time Protocol
What keeps the time across a network synchronized?
an NTP server
What port does the NTP server listen on?
UDP 123