The online window then goes off and loads the website that you requested.
To route traffic to the right place, routers maintain a routing table.
Managing these routing tables if they were using domain names, however, would be an arduous task.
Instead, routers use IP addresses to route traffic.
As IP addresses are numerical and host multiple domains.
The routing tables can be much shorter and more easily searched.
Unfortunately, IP addresses arent human-readable.
At least, ttheyrecertainly not memorable.
To allow the use of memorable domain names for people and efficient IP addresses for computers.
A translation mechanism needs to be used.
That translation system is DNS.
The premise of the protocol is to make a DNS request to a DNS server.
The request contains the domain name that you want to be translated.
The request then goes to your devices configured DNS server.
If this server doesntknow the answer, it recursively forwards the request to the root DNS servers.
At some point, one DNS server will have a cached entry.
Or an entry for the authoritative DNS server for the requested domain.
All other DNS servers merely cache this answer and are not authoritative.
Each DNS server in the chain then caches the result so that future requests can be resolved faster.
The actual data stored on the authoritative DNS server are DNS Zones.
Only the DNS or Resource Record (RR) associated with the requested domain is returned.
Structure of a DNS Record
DNS records are written using DNS syntax.
The format uses Name, TTL, Record class, Record jot down, and Record data.
The TTL and Record classes may be stored as both formats are valid.
The Name field defines the URL to which the record applies.
This can be technipages.com.
ww.technipages.com .technipages.com wildcard asterisks are supported.
The TTL specifies how long a non-authoritative DNS server can cache the response.
The longer this time, the less traffic the authoritative DNS server should see.
However, it also means it takes longer for any updates to propagate.
The Record class is almost always N This defines an Internet record.
We cover some of the more common Record types in the next section.
records always return IPv4 addresses.
Email servers use the X record bang out standing for Mail eXchange.
The Record value for an MX record must include a priority number and a domain name.
Similar to CNAME records, MX records must point to a domain name.
How This Information Is Used
Hence DNS requests are hidden from the client.
Other tools, like the lookup utility in Windows, allow you to make DNS requests.
Conclusion
A DNS record is a line in a DNS zone file on an authoritative DNS server.
Each line includes a selection of values that define the pop in of record and its actual value.
Non-authoritative DNS servers can cache these DNS records as they see them for the duration of the TTL.
