DNS in a nutshell part two (For dummies)

[daimer77]

DNS clarification needed.

Hello zimbra team and community, I have struggled a few days with the installation of 4.0.3, but without the necessary luck/skills to complete it.

It seems that my problems are strictly DNS related, and I have kindly been suggested to read the existing DNS related threads in the forum carefully. Among these I have read DNS in a nutshell.

Well I did read them, but none of the threads have lead to a full understanding of the DNS and Zimbra relation, nor have I found a thread which DNS issue description matches mine.

So... I will now describe my setup and my problems. And then I will write DNS in a nutshell part 2, because I believe that a situation like mine requires a better understanding of the need for a DNS (setup) during a Zimbra installation.

My setup:

Server A (DNS server - ip q.q.q.q)
Server B (Webserver hosting mydomain.com - ip x.x.x.x)
Server C (Zimbra server with domain name mail.mydomain.com - ip y.y.y.y)

Questions:

1) Do I need to have a bind server installed on Server C in order to satisfy ZCS ? Or can I just stick with my already configured DNS on Server A ?

2) The server A has an "A record" for mydomain.com called mail.mydomain.com where mail.mydomain.com points to server C with ip y.y.y.y - is this correct in zimbra terms ?

3) Server C (The zimbra server) must be a DNS master for it's own domain in this case: mail.mydomain.com ?

4) So the Zimbra server DNS is master for it's own domain, and just DNS cache for all other domains ?

5) What I am not sure of is wether the DNS server (Server A) should have mail.mydomain.com as a fully qualified domain and not just an "A record" under the domain mydomain.com. In other words; Do I need a full domain (mail.mydomain.com and mydomain.com will be seen as different domains) for the ZCS or can I just use a plain "A record" for the name mail.mydomain.com in the mydomain.com file ?

Sorry for my relative long list of questions but I really need some clarification, since I seem to misunderstand the terminolgy in the documentation.

Whenever I understand this DNS and Zimbra topic I will for sure post a bullet proof documentation for dummies

Thanks in advance, Best regards Daniel Mersebak

[dijichi2]

hi daimer77

1) Do I need to have a bind server installed on Server C in order to satisfy ZCS ? Or can I just stick with my already configured DNS on Server A ?

You should use DNS server already configured on Server A. Unless Server C is going to be a massive volume mail server, you should absolutely not setup another dns server on C, and even then there would have to be serious thought as to why you dont increase central dns server(s!) instead.

2) The server A has an "A record" for mydomain.com called mail.mydomain.com where mail.mydomain.com points to server C with ip y.y.y.y - is this correct in zimbra terms ?

Yes!

3) Server C (The zimbra server) must be a DNS master for it's own domain in this case: mail.mydomain.com ?

NOOOOOOOOO!

4) So the Zimbra server DNS is master for it's own domain, and just DNS cache for all other domains ?

NOOOOOOOOO!

5) What I am not sure of is wether the DNS server (Server A) should have mail.mydomain.com as a fully qualified domain and not just an "A record" under the domain mydomain.com. In other words; Do I need a full domain (mail.mydomain.com and mydomain.com will be seen as different domains) for the ZCS or can I just use a plain "A record" for the name mail.mydomain.com in the mydomain.com file ?

Do not setup FQDNs in DNS - it is possible of course to specify absolute hierarchies but rarely is it a good idea. Setup an MX and A record for your mailserver in the appropriate zone file. In this case with a bind server on A, something like this in the mydomain.com.zone:

(mail.mydomain.com. IN A y.y.y.y - this would work, but not recommended)
mail IN A y.y.y.y
mydomain.com. IN MX 10 mail.mydomain.com.

The MX record should not be an IP address or a CNAME, it should point to an existing FQDN (which you've just setup in the line before).

Sorry for my relative long list of questions but I really need some clarification, since I seem to misunderstand the terminolgy in the documentation.

Hey, absolutely no problem. Trouble is, mail servers have always traditionally been setup by sysadmins who should know all this stuff as basic fundamental of their job. However, with the advent of packages like zimbra which are so easy to install and use, it has completely changed the demographics of who uses it, which is fantastic. I'm a longtime sysadmin and although it's occasionally exasperating to see the same questions asked over and over in the forum, its also great to people trying this sort of software who would never have stood a snowballs chance in hell with other existing opensource software. Zimbra has completely turned round a previously stagnant and embarassingly crude sector of the opensource market, thankyou Zimbra

[unclecameron]

WOW that helped

I have installed mail servers many times, but the documentation just wasn't clear, so I would up attempting to install BIND on server C, when I was already using TinyDNS as my primary DNS on server A. I use tinydns because BIND is a big pain in the butt, but in this case I wound up delving deep into BIND and saying evil things about it. Anyway, thanks for the post, and maybe they could include parts of this in the manual, I have worked for days on this. Nice application though, happy to get it running

Thanks again,
Cameron
San Diego

[nxnw]

Originally Posted by daimer77

My setup:

Server A (DNS server - ip q.q.q.q)
Server B (Webserver hosting mydomain.com - ip x.x.x.x)
Server C (Zimbra server with domain name mail.mydomain.com - ip y.y.y.y)...

Respecting the above, would I be correct in understanding (wrt both the question and the answer) that we are talking about three servers in the same private IP range, as in:

Server A (ip 192.168.1.q)
Server B (ip 192.168.1.r)
Server C (ip 192.168.1.s)?

[unclecameron]

nah, doesn't really matter, you could make them whatever, mine were on 66.11.112.xxx and 66.11.124.xxx, just double check them or the install scripts will snarl at you and give you errors like unable to stat some slapd.conf file, which is bogus, really what that means is it can't find the right MX record.

Thanks,
Cameron Camp