Hey guys and welcome back. So in the previous nugget we had looked at some tools that we
could use to make particular DNS requests, those were their forward lookups as well as
reverse lookups. Now in the output of those tools we happen to see references to particular
records. So like I say the very first record is that A record and when we have an A record
what we're talking about is that this record is actually going to have IPv4 information
about a particular domain. So if you happen to have a particular domain such as maybe
say cloudflare.com and that might point to an IP address of let's say 1.1.1.1 this would
be an IPv4 address therefore that information is going to be stored in the DNS A record.
Okay now the next one is not relating to IPv4 you can probably guess the next one I'm going
to talk about is relating to IPv6. So this is what is called an AAAA record or a quadrature
record I've heard also be called or a quadruple A if you prefer. Now this is going to be the
same type of information relating to an A record but like I say inside it we're going to see that
hexadecimal IPv6 addressing. So that really is the only difference we're going to see here with
respect to our A record and our quadruple A record. The next record I just want to briefly
mention to you is one called the CNAME record. Now this record is all about passing information
between particular domains now crucially this doesn't actually relate to IP addressing information
this is about the domain names themselves in fact I should actually add that this can also relate to
sub domains to okay which like we talked about before that could be like drive.google.com that
information being passed around will be related to the CNAME record. Now recall in the previous
nugget we happened to use the reverse lookup so we could say host for a particular IP address
and we could see that we get information relating to a particular domain. The actual information
here that we are drawing from is what is called the pointer record this is something I've referred
to oh get my drawing pen on the go this is something referred as the PTR record otherwise
known as pointer. This can be thought of as like the mirror opposite the inverse mapping of the A
record like I say the A record is going to give you the IP address from the domain name the pointer
record is going to give you the domain name when you supply an IP address. Now the reality is there
are a ton more DNS records available we can have things such as an MX record this happens to relate
to mail servers you may recall that when we happened to use I believe it was the host command
say for example I did host google.com but also getting information relating to the mail we can
actually derive this information from that MX record and like I say there are even more records
such as the SOA record this is going to store administrative information about a particular
domain we can also have a TXT record these allow you to store text data within a particular record
and we can also have the SRV record which will allow you to actually detail particular information
relating to ports on a particular service so like I say we have a whole bunch of different records
and the reality is for the purposes of the examination you do not have to be too worried or
aware of all of the deep details of all of these records but if you happen to be deploying some
DNS server for real and the real world of course you do want to be aware of what these different
records are how they can be implemented what they actually do so definitely I would advise
for the real world having a good grasp of these different records is going to make your life
much much easier but for now what I want to do is to move on and actually get hands on with respect
to our DNS server configuration and well that's what we're going to be talking about in the very
next nuggets I hope this has been informative for you and I'd like to thank you for viewing