Networking: Network Services Flashcards
“A” record
The most common resource record, used to point a certain domain name at a certain IPv4 IP address
Anycast
A technique that’s used to route traffic to different destinations depending on factors like location, congestion, or link health
Automatic allocation
A range of IP addresses is set aside for assignment purposes
Caching and recursive name servers
They are generally provided by an ISP or your local network, and their purpose is to store domain name lookups for a certain amount of time
CNAME
A resource record used to map one domain to another
DHCP discovery
The process by which a client configured to use DHCP attempts to get network configuration information
Domain Name System (DNS)
A global and highly distributed network service that resolves strings of letters, such as a website name, into an IP address
DNS zones
A portion of space in the Domain Name System (DNS) that is controlled by an authoritative name server
Domain
Used to demarcate where control moves from a top-level domain name server to an authoritative name server
Domain name
A website name; the part of the URL following www
Dynamic allocation
A range of IP addresses is set aside for client devices and one of these IPs is issued to these devices when they request one
Fixed allocation
Requires a manually specified list of MAC address and the corresponding IPs
Fully qualified domain name
When you combine all the parts of a domain together
IP masquerading
The NAT obscures the sender’s IP address from the receiver
MX record
It stands for mail exchange and this resource record is used in order to deliver email to the correct server
Name resolution
This process of using DNS to turn a domain name into an IP address
Network Address Translation (NAT)
A mitigation tool that lets organizations use one public IP address and many private IP addresses within the network
NS record
It indicates other name servers that may also be responsible for a particular zone
NTP servers
Used to keep all computers on a network synchronized in time
Pointer resource record
It resolves an IP to a name
Port forwarding
A technique where specific destination ports can be configured to always be delivered to specific nodes
Port preservation
A technique where the source port chosen by a client, is the same port used by the router
Proxy service
A server that acts on behalf of a client in order to access another service
Quad A (AAAA) record
It is very similar to an A record except that it returns in IPv6 address instead of an IPv4 address
Recursive name servers
Servers that perform full DNS resolution requests
Reverse lookup zone files
They let DNS resolvers ask for an IP, and get the FQDN associated with it returned
Reverse proxy
A service that might appear to be a single server to external clients, but actually represents many servers living behind it
Round robin
It is a concept that involves iterating over a list of items one by one in an orderly fashion
SRV record
A service record used to define the location of various specific services
Start of authority
A declaration of the zone and the name of the name server that is authoritative for it
Top Level Domain (TLD)
The top level of the DNS or the last part of a domain name. For example, the “com” in www.weather.com
Time-To-Live field (TTL)
An 8-bit field that indicates how many router hops a datagram can traverse before it’s thrown away
Two-factor authentication
A technique where more than just a username and password are required to authenticate. Usually, a short-lived numerical token is generated by the user through a specialized piece of hardware or software
TXT record
It stands for text and was originally intended to be used only for associating some descriptive text with a domain name for human consumption
Types of DNS servers
There are five primary types of DNS servers; caching name servers, recursive name servers, root name servers, TLD name servers, and authoritative name servers
Virtual Private Network (VPN)
A technology that allows for the extension of a private or local network, to a host that might not work on that same local network
Zone Files
Simple configuration files that declare all resource records for a particular zone
