why To Use CNAME record ????

srnerkar1 · 12-03-2005, 04:34 AM

Hello,
I want to set up DNS server with my Redhat 9 machine. So for what this CNAME record is used in DNS files. What problem is solved by that and How TO specify that record in the forward zone file then??????????

Please Help Me Here.....

Thank YOU.......

musicman_ace · 12-03-2005, 05:09 AM

I don't have my DNS cookbook right in front of me to give you all the proper details, but they are alias's to the machine.
Your local webserver's hostname might be named websvr in your domain of mydomain.com giving you a full qualified name of websvr.mydomain.com. Since this is your webserver, your likely to want people to access it by www.mydomain.com, so you would create an alias or cname record.

If your redhat9 box is going to host ftp and www, you'll want the following cname records

Code:

websvr     IN      A      192.168.1.3
www        IN      CNAME  websvr
ftp        IN      CNAME  websvr

So this means that if I open a browser to websvr.mydomain.com or to www.mydomain.com, I should get to the IP address 192.168.1.3
If I use an FTP client, I should be able to ftp to any of the following:
websvr.mydomain.com
ftp.mydomain.com
192.168.1.3

=====
I hope the spacing looks good and I remembered all that correctly

srnerkar1 · 12-31-2005, 12:00 AM

thank you sir for ur previous reply.
if i give name "abc" as alias to my webserver as an example

websvr IN A 192.168.1.3
abc IN CNAME websvr

so here can I access my webserver as http://abc only from my browser?
similarly if i want to access this server with "abc" name only in my intranet systems (DONT WANT TO SHARE THAT SERVER ON INTERNET), Can i do that and if yes then in what way???

Thank you in advance.............

aq_mishu · 12-31-2005, 12:24 AM

Code:

$TTL    86400
$ORIGIN mydom.org.
@                       1D IN SOA       ns1.mydom.org. admin.mydom.org. (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum
 
; Domain declarations
@                       1D IN NS        ns1.mydom.org.
 
; Mail exchangers
@                       1D IN MX 10     mail.mydom.org.
 
; A records
www                     1D IN A         192.168.0.2
mail                    1D IN A         192.168.0.3
 
; CNAME records
ns1                     1D IN CNAME     www.mydom.org.
forum                   1D IN CNAME     www.mydom.org.
webmail                 1D IN CNAME     mail.mydom.org.

By this, my mail exchanger is the mail.mydom.org which the 192.168.0.3 is assinged as an Address (A) record. Then the ns1.mydom.org is 192.168.0.2 but by the same time, this 192.168.0.2 is serving as the www.mydom.org and also serving the forum.mydom.org. Now if i type http://www.mydom.org or http://forum.mydom.org then my pc will connect to ns1.mydom.org and serve data from there. The same way, basically we use eudora to check mails and there I use mail.mydom.org as my mail server. But while using webmail, I can then use the same server but more userfriendly way... http://webmail.mydom.org and it'll also connect to the mil.mydom.org.

Here remember one thing, when you use any webpage, you must run the webserver in that machine. And so for others... And also you must set your other pc's DNS server address to that DNS box's ip. Only then they will resolve the ip from your given url. Hope now it'll help you...

Mishu~~