Network Services Flashcards
Zone transfer
Sharing of information between DNS servers about which domain names they have and their associated IP addresses
Network Time Protocol (NTP)
Synchronizes clocks between systems communicating over a packet-switched, variable-latency data network; sent over UDP using port 123
Scope
A list of valid IP addresses available for assignment or least to a client computer or endpoint device on a given subnet
DHCP Reservation
Excludes some IP addresses from being handed out to devices unless they meet a certain condition
DHCP Relay
Forwards DHCP packets between clients and servers (only if not in the same subnet or network)
IP Helper
Forwards several different kinds of UDP broadcasts across the router and can be used in conjunction with the DHCP relay
Upon whom do we rely for DNS services?
Our ISPs
what is the top level domain in DNS?
the .com part of the address
What is the root level domain in DNS?
.com, .net, etc.
Top-level domain
.com, .eu, etc.
second level domain?
diontraining.com
subdomain?
support.diontraining.com
host level domain?
refers to a specific machine or device on the network
A Record?
links a host name to an IPv4 address
AAAA Record
links a hostname to an IPv6 address
CNAME Record
canonical name; points a domain name to another domain name; point an old domain to a new one you started
MX (Mail Exchange) Record
directs emails to a mail server
Start of Authority (SOA) record
stores important information about a domain or zone; when it was last updated, very important for zone transfer (sends dns record data from the primary nameserver to a secondary nameserver)
PTR Record
pointer record; correlates an IP address with a domain name
TXT Record
Text; adds text into the DNS; mostly used to prove domain ownership, and spam prevention (like what we do with proofpoint)
SRV Record
Service; specifies a host and port for a specific services
NS Record
nameserver; indicates which DNS nameserver has the authority
TTL (Time to Live)
Tells the DNS resolver how long to cache a query
Recursive Lookup
DNS Server communicates with several other DNS servers to hunt down the IP address and return to the client
Iterative Lookup
Your DNS resolver asks for IP, if not it asks the next server, and so on and so forth
Network Time Protocol (NTP)
Synchronizes clocks between systems communicating over a packet-switched, variable-latency, data network; sent over UDP Port 123; important so we can all have the same time. Why so important? A lot of out security protocols rely on time to work
