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OK, in the last lecture, we had a brief introduction to the DNS server not to complete unqualified



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domain name service names that will be used to search and submit DNS queries or declined for resolution.



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You must have a list of DNS suffixes that can be appended to these days DNS names for DCP Glines.



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This can be said about assigning the DNS domain name option and providing a single DNS suffix for the



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client to append and use in searches.



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Now, in this lecture, we're going to talk about the DNS record type's.



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Address mapping, record it now host is called an area record, and what it gives is it gives you the



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IP address of a domain or a host in IP version six.



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It is called a quad or four times a record.



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Now, your earlier records.



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So these records.



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Let me take the pointer.



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Yeah.



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So these records resolve the host names to IP addresses, but what happens if you know the IP address



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and then you want to hostname?



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Well, there is a record for it too.



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That is a pointer record which formulates back or points back to the name now.



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Canonical name record.



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That is the C name record.



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Now the C name record can be used as an alias to a hostname or another hostname.



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When a DNS client requests a record that contains a canonical name which points to another host name,



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the DNS resolution process is repeated with a new host.



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So basically C name is used to, you know, point to another host name and then this process continues.



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Well, finally, the new hostname is the next is the main exchange, a record that is the imex record



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of the Amex record points to the mail exchanger for a particular host.



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Now, DNS is structured so that you can actually specify several e-mail exchanges for one host.



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So basically the Amex record is involved in sending and receiving e-mails through a particular server



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name server records.



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That is, the NSA records, not NSA records, specifies that a DNS zone such as, let's say, Google



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dot com is delegated to a specific authoritative name server and it provides the address of the name



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server.



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So it is authoritative name server, authoritative name.



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So it's basically, let's say www.youtube.com and Google is the authoritative name server.



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Dot com is the root level server.



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We have seen the different route domains or the different dot com designations in the last lecture.



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And I have told you that the domains that is top level domain or the root level domains and dot com



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is one of the root level domain and therefore authoritative names.



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Server is Google.



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Reverse lookup point records allows a DNS resolver to provide an IP address and receive a host name.



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So what what area code does basically?



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So what area code does?



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What this record does is basically to give the name and it will return an IP address.



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OK, it will return an IP address.



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But in case of this reverse lookup pointer, you give an IP address.



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So it allows the DNS resolved to provide an IP address and receive a hostname.



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So it's a voiceover subprocess.



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The next is certificate record, that is a solid record.



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Now the certificate of record stores and certificates, for example, Bishkek's that is public infrastructure,



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Speccy, BGP and so on.



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Now, when you go to w w w dot Google dot com in the browser in November, suppose this is of a bar



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and here is w w w dot com.



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There is a small lockyear here.



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OK, if the certificate or if this website is protected then you click here.



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There is a box which tells you that certificate is stored.



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Now where is the certificate or the certificate is actually stored in the certificate record.



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OK, next is service location.



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That is the S of record.



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A service record is a generalized service location record which is used for new protocols instead of



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creating protocol specific records.



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Then is that the extra costs, the extra guards are used to provide authentication of mail sent and



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received by the same e-mail system.



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It basically works on the sender.



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Is your policy, for example, if any one of you has created a website or they won't have the host the



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website, they might be knowing that when you want to verify your website, you have to add the structure



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in place and you have to verify that the extra record after a certain point from the original server.



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And then if that is verified by the mail exchanger, then you are allowed to send and receive third



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party emails on your.



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The next is the esoterica that is the start of authority now, this record appears at the beginning



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of the DNA on file, and it indicates the authoritative name server, for example, Google for the current



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DNA.



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It also provides the contact details for the domain administrator domain serial number and information



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on how frequently DNS information for the zone should be refreshed.



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Now, in the next lecture, I'm going to discuss about the different types of business and external



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internal DNS, but before going ahead, we are going to use a DNS dumpster that is dumpster practical,



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where you'll find how to calculate or how to find out the information from a domain name.



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So it's a great practical and I recommend you to not skip the spectacle.



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I will see you in the next lecture.