DNS Records

In order to find resources on the network, computers need a system to look up the location of resources. Check out / itfreetraining or itfreetraining.com for more of our always free training videos. This video looks at the DNS records that contain information about resources and services on the network. The client can request these records from a DNS server in order to locate resources like web sites, Active Directory Domains and Mail Servers just to name a few.
ITFreeTraining.com/handouts/dn...
In this video
This video will look at the following DNS records:
Host (A and AAAA): Contains IP Addresses for IPv4 and IPv6 hosts
Alias (CNAME): Works just like a shortcut for files except for DNS records.
Mail Exchange (MX): Holds the address of mail servers for that domain.
Service Record (SRV): Holds the address of services on the network. E.g. Active Directory DC's.
Start of Authority (SOA): Contains information and configuration for a zone file.
Name Server (NS): Contain the address of other DNS servers for that zone.
Pointer (PTR): Reverse look up record allowing a hostname for an IP Address to be look up.
Host (A and AAAA)
The host record is used to store the address of a hostname. "A" is used for IPv4 and AAAA (Quad A) for IPv6. These can be created manually in DNS or if dynamic DNS is enabled and the client can register its hostname and thus its IP Address with the DNS server.
Alias (CName)
A canonical name or CName record provides an alias service in DNS. A CName effectively points to another A or Quad A record. When the client requests the hostname that is contained in the CName, they are given the IP Address that is contained in the A record or Quad A record. The advantage of a CName is that it can provide a simple name to the user rather than a more complex server name. For example, instead of having to remember FS27 for the local file server, a CName of FS could be used to point towards the server FS27. CName's can also be used to transparently redirect network traffic. For example, if you changed you mind and wanted to redirect the user to FS28 you would only need to change the CName record to point to FS28 rather than FS27. It should be remembered that the old record may exist in the client cache and may take some time to expire.
Mail Exchange (MX)
The mail exchange record contains a mail server that is able to process mail for that domain name. When a mail server wants to deliver mail, it will perform a DNS lookup asking the DNS server for an MX record for that DNS Domain name. The mail server will then attempt to deliver mail to that server. The mail server does not need to have the same DNS name as the mail that is being delivered, it simply needs to understand how to process mail for that DNS domain name.
The MX record also has priority value that can be configured. If two or more MX Exchange records exist for the same DNS Doman name, the MX record with the lowest priority will be tried first. If this fails, the MX record with the next lowest value will be tried until the mail is delivered. Often large companies will have multiple mail severs for incoming mail. In some cases, these additional mail servers may be located on different sides of the globe in case there is a long network outage.
Service Record (SRV)
Service records allow clients on the network to find resources on the network. Active Directory creates a number of service records in DNS to allow clients to find resources like Domain Controllers. This is why Active Directory cannot operate without DNS. A single service record has a number of data fields associated with it. These include, service, target, port and priority. Service records are normally created automatically by applications assuming that your DNS server allows dynamic updates.
Start of Authority (SOA)
There is one start of authority record (SOA) for each zone. Even though the SOA is technically a DNS record, essentially modification of the SOA record is performed through the properties of the DNS zone. Looking at the data in the SOA record, you can configure options for the zone like the primary name server for that zone (DNS servers that hold the master records for the zone), the e-mail address of an administrator, serial number (Incremented each time a change is made in the DNS zone) and the refresh time for the zone (How often a secondary zone should query a master for changes).
Video description to long for KZread. For full description please see itfreetraining.com/70-642/dns-...
See / itfreetraining or itfreetraining.com for our always free training videos. This is only one video from the many free courses available on KZread.
References
"MCTS 70-640 Configuring Windows Server 2008 Active Directory Second edition" pg 458 -- 459
"Installing and Configuring Windows Server 2012 Exam Ref 70-410" pg 236-237
"SRV record" en.wikipedia.org/wiki/SRV_record

Пікірлер: 176

  • @itfreetraining
    @itfreetraining10 жыл бұрын

    Thanks, glad to hear that you like the videos.

  • @itfreetraining
    @itfreetraining10 жыл бұрын

    No problem at all. Thanks for watching.

  • @JDBoelter
    @JDBoelter6 жыл бұрын

    Good presentation - clearly miked and clearly delivered, good plain English explanations. I feel as if I understand SOA and NS records much better now. Thanks!

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're most welcome! Thank you for your kind feedback. :)

  • @farukhshaikh2672
    @farukhshaikh26729 жыл бұрын

    Its just due to your videos i am able to understand windows servers. May God bless you guys.

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    Farukh Shaikh Thanks very much, glad we could help you

  • @jdphd123
    @jdphd12310 жыл бұрын

    I am so glad that you made available this information and video.* Also the narration and manner used.

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    Thanks very much. Glad to hear that you like the video.

  • @richardcummins3649
    @richardcummins36497 жыл бұрын

    You have a collection of great videos. Very informative!

  • @itfreetraining

    @itfreetraining

    7 жыл бұрын

    Thanks for the great feedback! We appreciate you choosing ITFreeTraining!

  • @kittnlogic
    @kittnlogic4 жыл бұрын

    Thank you for the clear and concise lesson! So helpful!

  • @waseemhasan5372
    @waseemhasan53722 жыл бұрын

    Much appreciated the graphics and explanation. Keep up the amazing work!

  • @itfreetraining

    @itfreetraining

    Жыл бұрын

    Much appreciated!

  • @user-tf9lx9iy1s
    @user-tf9lx9iy1s9 жыл бұрын

    very good ,this lesson explain the knowledge very well. thanks

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    Thanks very much. Glad we could help.

  • @mcsephiroth1312
    @mcsephiroth13123 жыл бұрын

    Thank you for this explanation. I understood it much better than Google IT Training's explanation.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    You are welcome!

  • @doubledogdare610
    @doubledogdare61010 жыл бұрын

    Thanks Sir! I have been looking for somthing that can help me with my mail server but finally! I didnt know that i was using the wrong record...

  • @onlyeyeno
    @onlyeyeno3 жыл бұрын

    This is a good and very well presented video and I'm very grateful for You making and sharing it. That said I think it could have been even better if it had used more "graphical slides", if the type You used when explaining (clarifying) the "MX record". Showing an "over view" of where (in the network) the different records would be "held".And how they would "querried and answer" to fulfill their function is something I believe would facilitate learning and grasping the context of, and relation between the different records. Again many thanks for making and sharing this excellent content Best regards.

  • @sordodikra5129
    @sordodikra51297 жыл бұрын

    You are truly amazing. THANK YOU.

  • @itfreetraining

    @itfreetraining

    7 жыл бұрын

    You're welcome! Thanks for the amazing feedback. :)

  • @adamwilkinson007
    @adamwilkinson00711 жыл бұрын

    Thanks guys this is brilliant your going to help me get me through my exams for 70-410 :-)

  • @sergei4517
    @sergei45174 жыл бұрын

    Excellent right to the point explanations. Thanks a lot!

  • @itfreetraining

    @itfreetraining

    4 жыл бұрын

    Glad it was helpful!

  • @MrPrasad730
    @MrPrasad73010 жыл бұрын

    Very clear explanations. Keep up the good work ! thx

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    Thanks very much. More videos to come.

  • @itfreetraining
    @itfreetraining10 жыл бұрын

    Thank you.

  • @andreigheorghe5402
    @andreigheorghe540211 жыл бұрын

    I love your presentations.

  • @itfreetraining
    @itfreetraining10 жыл бұрын

    Thanks very much.

  • @abhijeetnegi6484
    @abhijeetnegi64843 жыл бұрын

    i still watch ur awesome expalnations, and it is jus so good.

  • @ramziboutaoua3298
    @ramziboutaoua32983 жыл бұрын

    You got the art of explaining, you are the best

  • @TebogoMotlhale

    @TebogoMotlhale

    3 жыл бұрын

    Yeah, he is best by FAR. The others tend to fall into the trap of starting off by using too many SIMPLE analogies and then when the topic goes deeper, it gets harder for them to find perfectly equivalent concepts in the analogy, to keep using that analogy in a manner that is STILL relevant/meaningful to the topic 😁

  • @ramziboutaoua3298

    @ramziboutaoua3298

    3 жыл бұрын

    @@TebogoMotlhale exactly, some times calling things by their real names works much better then exaustive analogies

  • @itfreetraining
    @itfreetraining11 жыл бұрын

    Thanks Adam! Good Luck taking them

  • @CLAIREdujardin
    @CLAIREdujardin10 жыл бұрын

    Very clear explanations. Keep up the good work !

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Thanks for watching.

  • @greatsky8226
    @greatsky82262 жыл бұрын

    Competent video with brilliant rhetoric.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Thanks very much.

  • @eavincentg
    @eavincentg6 жыл бұрын

    Thank you. Excellent tutorial!

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    Thank you for your great feedback!

  • @cskillet2003
    @cskillet20034 жыл бұрын

    Great video on common resource records!

  • @itfreetraining

    @itfreetraining

    4 жыл бұрын

    Thanks!

  • @albixhako1727
    @albixhako17273 жыл бұрын

    Thank you. Very simple and informative way.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Glad it was helpful!

  • @hisatnam
    @hisatnam4 жыл бұрын

    Wow, I liked it. Thanks for sharing this with us.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Thanks for watching.

  • @lakminarathnayake2165
    @lakminarathnayake21654 жыл бұрын

    Great Knowledge Video of DNS records I ever see

  • @raghuveershetty2922
    @raghuveershetty29228 жыл бұрын

    nice clear explanation with examples and with easy english

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    Thanks!

  • @bulelanicutalele7940
    @bulelanicutalele79407 жыл бұрын

    Helpful indeed, clear explanation

  • @itfreetraining

    @itfreetraining

    7 жыл бұрын

    Thanks for the great feedback and for watching!

  • @enizi1
    @enizi19 жыл бұрын

    Thank you very much ,,it is very helpful.

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    Thanks, glad we could help.

  • @TheAmazeer
    @TheAmazeer6 жыл бұрын

    Great job.. a value added would have been to show Dns configuration but maybe you did it on another video

  • @sencadas32
    @sencadas328 жыл бұрын

    Congratulations! Nice video!

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +Vinicius Thank you very much, we're glad to hear your feedback.

  • @DillonMinasian
    @DillonMinasian11 жыл бұрын

    Great Video, helped explain a lot. Thanks :)

  • @hemang81
    @hemang816 жыл бұрын

    Thanks...It's been very very informative..!!

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're very welcome!

  • @balajidhatchanamoorthy3198
    @balajidhatchanamoorthy31988 жыл бұрын

    superb,its really useful to me to understand thanks a lot

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +Balaji Raina You're most welcome.

  • @itfreetraining
    @itfreetraining10 жыл бұрын

    Thanks.

  • @arvindpal8070
    @arvindpal80703 жыл бұрын

    Thanks to explain DNS record in easy to understand

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    It's my pleasure

  • @patrickjohnyap2112
    @patrickjohnyap211210 жыл бұрын

    very well said :) thanks for all the videos

  • @chrisharrid5725
    @chrisharrid57253 жыл бұрын

    Really helped me. Thanks for that.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    You're welcome!

  • @chandranaggmchandranag8818
    @chandranaggmchandranag88183 жыл бұрын

    Finally found this Thank you sir

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Thanks for watching.

  • @GunelMammadova93
    @GunelMammadova933 жыл бұрын

    thanks for the video! Learned a lot from it

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Glad it was helpful!

  • @felixmintah8632
    @felixmintah863210 жыл бұрын

    Great video

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    Thanks very much.

  • @precisionit1422
    @precisionit142210 жыл бұрын

    Very good videos with full clarity.Well done sir but no videos on AD DS backup and restore.pls upload sir.

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    Sorry about that, will get those videos done when we can.

  • @leo-rq2ei
    @leo-rq2ei5 жыл бұрын

    Nicely done 👏👏

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    Thanks!

  • @bryanmendoza3919
    @bryanmendoza39194 жыл бұрын

    great it will help me on how to recognize those records in DNS

  • @itfreetraining

    @itfreetraining

    4 жыл бұрын

    Glad we could help.

  • @shubhamjoshi_SELabs
    @shubhamjoshi_SELabs8 жыл бұрын

    Excellent! Thank you

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +shubham joshi We're glad you think so! You're welcome and thank YOU for watching!

  • @boatengokyere-darko3806
    @boatengokyere-darko380610 жыл бұрын

    I love it soo much, Cheers.

  • @MsAshutosh123
    @MsAshutosh1233 жыл бұрын

    Can you make a video on different types of http error codes in the same whey.your videos are simple and easy to understand

  • @netaishvasistha9875
    @netaishvasistha987510 жыл бұрын

    Great Video very well Expained Thx

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    Thanks very much and thanks for watching.

  • @TahaIsmailCanada
    @TahaIsmailCanada10 жыл бұрын

    Thanks so much

  • @itfreetraining

    @itfreetraining

    10 жыл бұрын

    No problem at all. Thanks for watching.

  • @shiwang4809
    @shiwang48092 жыл бұрын

    So helpful!

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Glad it was helpful!

  • @alihaleem2705
    @alihaleem27056 жыл бұрын

    thanks again .. great video

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're welcome!

  • @roxriver91
    @roxriver918 жыл бұрын

    thank you, excellent.

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +roxriver91 You're welcome! Thanks for watching.

  • @thaernidal9832
    @thaernidal98329 жыл бұрын

    it's helpful thank you

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    You're welcome, glad the video was helpful!

  • @YouSsefDjOGeekOfficial
    @YouSsefDjOGeekOfficial6 жыл бұрын

    well explained thanks !

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're very welcome!

  • @mattia7737
    @mattia77373 жыл бұрын

    thank you very much it really help me

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Thanks for watching.

  • @bder88
    @bder884 жыл бұрын

    thx alot , great video

  • @nifink.antony6953
    @nifink.antony69534 жыл бұрын

    Amazing..Nice

  • @lucha_ftw
    @lucha_ftw6 жыл бұрын

    Great stuff

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    Thank you!

  • @Rassamaxa1000
    @Rassamaxa100010 жыл бұрын

    very good!!thanks

  • @gonzalotrepiana6628
    @gonzalotrepiana662810 жыл бұрын

    thanks so much!!

  • @kedmnc895mna
    @kedmnc895mna6 жыл бұрын

    This is great.

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    Excellent, thanks for the wonderful feedback.

  • @nithinkg2880
    @nithinkg28808 жыл бұрын

    great video

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +Nithin Kg Thanks!

  • @clovisgrenier
    @clovisgrenier6 жыл бұрын

    THANK YOU

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're very welcome!

  • @Tymonello
    @Tymonello5 жыл бұрын

    thanks, it is helpful

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    Thank you for watching!

  • @mez1486
    @mez14865 жыл бұрын

    I do everything right but the SPF record can't be verified so frustrating!

  • @ramireddy5071
    @ramireddy50717 жыл бұрын

    excuse me sir i have a doubt what do you mean by resource records?(my exam question) ca i write your explanation for that question thank u sir

  • @eleftheriosiliopoulos8796
    @eleftheriosiliopoulos87968 жыл бұрын

    it is valid 100% for the 70-411.

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +LEF ISOS Excellent, we're always excited to confirm our content lines up with the Microsoft exams.

  • @user-oq1id3sv9d
    @user-oq1id3sv9d6 жыл бұрын

    thanks

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    You're most welcome!

  • @messiassantos5140
    @messiassantos51405 жыл бұрын

    Thank you I mean it u helped me

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    You're most welcome, thanks for watching!

  • @shihabuddinnori8236
    @shihabuddinnori82367 жыл бұрын

    thanks thanks thanks thanks

  • @Thepankaz1
    @Thepankaz17 жыл бұрын

    For CNAME Record where does it maintain ip for web1, cname stors alias but how is actual ip is obtained for web1, is another call made to another dns server which maintains a A record or same server maintains both CNAME and A record.

  • @itfreetraining

    @itfreetraining

    7 жыл бұрын

    The resolver sees that it's a CNAME and begins its search over again at the root domain level. For example, if there is a DNS zone as follows: NAME TYPE VALUE -------------------------------------------------- bar.example.com. CNAME foo.example.com. foo.example.com. A 192.0.2.23 when an A record lookup for bar.example.com is carried out, the resolver will see a CNAME record and restart the checking at foo.example.com and will then return 192.0.2.23.

  • @vjnvisakh
    @vjnvisakh5 жыл бұрын

    nice.

  • @ziaullah9541
    @ziaullah95418 жыл бұрын

    awesome

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    Thanks!

  • @DzikuS-km8he
    @DzikuS-km8he8 жыл бұрын

    Nice

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    Thanks!

  • @srirama4580
    @srirama45809 жыл бұрын

    i have a live scenario.. Windows 2012 installed with AD and Dns. Standard configuration. noticed if i nslookup ip and hostname . all good if i use the fqdn there is 2 request time out and a reply. if i use fqdn with dot at the end its good. please help Thanks in advanc

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    Sri Rama I am not sure what the problem is here. Windows will normally add the dot at the end so you don't need to worry about it. It is strange that it requires it to be there. Have you configured your own root servers or are you forwarding the requests to your ISP?

  • @hunkmujeeb
    @hunkmujeeb6 жыл бұрын

    I am unable to ping Server 2K8r2 to win 7 host. I have created DNS forward and reverse records and allow ICMP also.

  • @itfreetraining

    @itfreetraining

    6 жыл бұрын

    What happens when you try to ping the IP address directly?

  • @syedjunaid7846
    @syedjunaid78464 жыл бұрын

    4:10 did you mean when a DNS server has an email it needs to end it needs to locate a mail server

  • @itfreetraining

    @itfreetraining

    4 жыл бұрын

    It is a little confusing. So essentially lets say that an e-mail server wants to send an e-mail to example.com. In order to do this, it needs to send the e-mail to the example.com mail server. So it performs a look up to find out where example.com mail server is. Essentially gets the MX record for example.com. The mail server then contacts the example.com mail server and transfers the mail to it.

  • @Mangokyaw
    @Mangokyaw Жыл бұрын

    I am so confused.. what are the differences between the MX, pop3, Imap4, snmp, smtp?

  • @itfreetraining

    @itfreetraining

    9 ай бұрын

    DNS MX (Mail Exchanger) Record: MX records are DNS records that specify the mail servers responsible for receiving email messages on behalf of a domain. MX records help route email messages to the correct destination by pointing to the mail servers' hostnames or IP addresses. MX records are essential for email delivery, as they determine where incoming email messages should be delivered within a domain. POP3 (Post Office Protocol version 3): POP3 is an email retrieval protocol used by email clients to retrieve email messages from a mail server. POP3 typically downloads email messages to the client's device, removing them from the server. This means that emails are stored locally, and changes made on the client do not affect the server's copy. POP3 is commonly used for downloading emails to a single device, like a computer. IMAP4 (Internet Message Access Protocol version 4): IMAP4 is another email retrieval protocol used by email clients to access email messages stored on a mail server. Unlike POP3, IMAP4 allows multiple devices to access the same mailbox simultaneously and keeps emails synchronized across all devices. Changes made on one device are reflected on the server and other devices. IMAP4 is suitable for users who want to access their emails from multiple devices and keep them synchronized. SNMP (Simple Network Management Protocol): SNMP is a network management protocol used for monitoring and managing network devices like routers, switches, and servers. SNMP allows network administrators to collect data and manage devices remotely by querying and configuring settings on network equipment. It is not directly related to email or DNS but is essential for network management and monitoring. SMTP (Simple Mail Transfer Protocol): SMTP is an email sending protocol used to send outgoing email messages from a client to a mail server or from one mail server to another. SMTP is responsible for routing and delivering email messages to their intended recipients. It works together with MX records and other email protocols. SMTP is essential for the delivery of email messages across the internet. In summary, DNS MX records help route email messages, while POP3 and IMAP4 are email retrieval protocols for accessing email messages stored on mail servers. SNMP is a network management protocol, and SMTP is an email sending protocol responsible for delivering email messages. These protocols serve different roles in the email and network communication process.

  • @Ragatokk
    @Ragatokk8 жыл бұрын

    How do I set up my server when I have it on a subnet? Say my external ip is 84.22.1.331 but my local ip is 192.168.1.2. How would I set up my www.website.com to be sendt to the server with the local ip of 192.168.1.2 ?

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +Ragatokk Your server is using a private IP Address. So you need to configure your home router to forward web traffic to that server. So in your router, forward port 80 to 192.168.1.2

  • @Ragatokk

    @Ragatokk

    8 жыл бұрын

    Thanks, but how do I do it when I have two servers on the same network?

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    +Ragatokk Multiple web sites can share the same IP Address. The web server should use the incoming DNS to work out what web site it is. However, you will not be able to have to servers using the same port unless you have two different public IP Addresses.

  • @bogdanM29
    @bogdanM295 жыл бұрын

    there's a difference between A Records and CName, CName can't be used for naked domain names.

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    CName are like a shortcut like that used in the file system. For example, if you had www.itfreetraining.com and itfreetraining.com you could create a CName to like one to the other. This way you only have one A record making it easier to manage.

  • @keplerdevelopers9636
    @keplerdevelopers96367 жыл бұрын

    Why there is not MX record when I nslookup www.hotmail.com ?

  • @itfreetraining

    @itfreetraining

    7 жыл бұрын

    Hotmail seems to want to use a CNAME record vs a traditional MX record. That's probably why.

  • @jgwood89
    @jgwood898 жыл бұрын

    When you said "another A record", did you mean another Alias Record?

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    That's correct.

  • @jgwood89

    @jgwood89

    8 жыл бұрын

    Thank you. Also, since PTR works the opposite of A records essentially, does that mean it also works the opposite of CNAME records?

  • @itfreetraining

    @itfreetraining

    8 жыл бұрын

    The A record maps a name to one or more IP addresses, when the IP are known and stable. The CNAME record maps a name to another name. It should only be used when there are no other records on that name. The A name must resolve to an IP, the CNAME and ALIAS record must point to a name. To answer your question: No, PTRs are not the opposite of CNAMEs. CNAMEs are similar to aliases and point to another hostname vs an A record which points to an IP.

  • @raghuveershetty2922
    @raghuveershetty29228 жыл бұрын

    if they start training institute in indian many students will benefit

  • @dean6845

    @dean6845

    8 жыл бұрын

    I'm studying computer networking for few weeks using web pages and youtube and I mostly encountered courses with indians (I hope that's how you call people from india) so I'm not sure if they even need teacher, since they are teacher itself :D Kidding, but sometimes they really are "know-it-all". Great video and explanations :) Peace

  • @kevinportillo1971
    @kevinportillo19715 жыл бұрын

    Out of everyhting from TCP/IP if find this topic the most difficult to remember !!!!

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    Networking isn't always intuitive so stick with it!

  • @Metallnsanity87
    @Metallnsanity875 жыл бұрын

    1.25 video speed is best

  • @mohamedabas942
    @mohamedabas9429 жыл бұрын

    i dont know the use of this stupid service record .. its allways spam filessrv like this ::::::: Firefox Setup 16.0.1SrvSrvSrv .. and i dont know how to stop it .. it creat about 50 - 74 file when i start any program or click any icon :S any one can help me in this ?

  • @itfreetraining

    @itfreetraining

    9 жыл бұрын

    Mohamed Abas I have not heard of this before. If you know which computer it is coming from I would do a check for the computer to see what software is installed. perhaps run a packet sniffer on the computer to work out which software is creating them. Perhaps it is Malware so I would do a check for that as well.

  • @rothscliff6086
    @rothscliff60864 жыл бұрын

    teaches better than Uni lol

  • @itfreetraining

    @itfreetraining

    4 жыл бұрын

    Thank you.

  • @michaelsiengo1
    @michaelsiengo12 жыл бұрын

    Am I the only one who thinks DNS is confusing as hell been trying to learn it for about a month

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    DNS can be difficult at first, is there anything in particular you are having problems understanding?

  • @mahdiehshahhosseinian3558
    @mahdiehshahhosseinian35582 жыл бұрын

    so confusing

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    What do you find confusing?

  • @CorporateMajdoorTrader
    @CorporateMajdoorTrader2 жыл бұрын

    Such a vague explanation

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    This is a pretty old video now. It helps if you watch the other DNS videos as well. We generally make the videos now so they can be watched by themselves. Is there anything in particularly you are having trouble understanding.

  • @thomasjones3224
    @thomasjones32245 жыл бұрын

    Your explanation of MX was very confusing.

  • @itfreetraining

    @itfreetraining

    5 жыл бұрын

    What was confusing? Perhaps we can help clear up any confusion. :)

  • @blackrockcity
    @blackrockcity4 ай бұрын

    Pro tip: don’t use Microsoft technologies or products

  • @SecureOpsWizard
    @SecureOpsWizard3 жыл бұрын

    Sorry but this is a terrible and hard to understand presentation for beginners. A more visual explanation of what's being said would've been helpful.

  • @itfreetraining

    @itfreetraining

    2 жыл бұрын

    Sorry to hear that. We are currently redoing the way we do videos so future videos should be better.

  • @itfreetraining
    @itfreetraining11 жыл бұрын

    Thanks very much.

  • @farhantanvir9650
    @farhantanvir96505 жыл бұрын

    Thank you.