There is DNS implemented in our setup but I am not able to understand some of the entries in the forward zone file. The DNS entries in the forward zone file, fion.co.in.zone are like:

$TTL 86400
$ORIGIN fion.co.in.
@ IN SOA localns1.fion.co.in. admin.fion.co.in. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum

IN NS localns1.fion.co.in.
IN MX 10 mail.fion.co.in.

I have the following queries with regard to the above file:

1) The hostname of the server is the same one on which it is hosted which is bssossapp01.snl.com. But, I am not able to understand the entry localns1.fion.co.in. Is it possible that there are multiple hostname aliases for a server?
2) How to determine the entry to be put in hostmaster-email directive which is showing as admin.fion.co.in in our setup?
3) How to determine the email-server-name in the MX record which is showing as mail.fion.co.in as above?

I hope, my query is clear of how to understand the entries in the forward zone file.

Please revert with the reply to my query.

Regards

1. Sure you can have multiple names for a host. The names are given either through the hosts files (/etc/hosts), or the zone file
2.This is the email of the administrator of the dns, i.e the person responsible for its maintenance. See here for details
3. Quoting from this
HTH

Thanks a lot for your answer. I had the following observations with regard to the 3 points on which I got the reply:

1) The remaining part of the forward zone file is like,

IN A 10.101.17.79

localns1 IN A 10.101.17.79
fiontelapps IN A 10.101.17.86
wsc IN A 10.101.17.87

So, that means the entry below in the file of

localns1 IN A 10.101.17.79

finds a match in the entry localns1.fion.co.in. IN SOA localns1.fion.co.in. admin.fion.co.in.?

Does that mean that additional host name localns1 which is now defined in the zone file could also be defined in the /etc/hosts file as

10.101.17.79 bssossapp01 localns1.fion.co.in

where bssossapp01 is the hostname of the machine?

2) The entry in hostmaster-email directive seems to be non-existent but still it does not seem to cause a problem in DNS configuration. So, can we conclude that even if the hostmaster-email does not exist, it is not going to affect the primary role of the DNS of name resolution?

3) Same reasoning as the point above seems to hold for the email-server-name in the MX record. The mail server specified, mail.fion.co.in seems to be non-existent. Can we conclude that even if the email-server-name in the MX record does not exist, it is not going to affect the primary role of the DNS of name resolution?

I hope, my queries above are clear.

Requesting a revert on the above points.

Regards

1 members found this post helpful.

1. Means that localns1.fion.co.in resolve to 10.101.17.79
Note that /etc/hosts is used locally. Other computers use the dns entry, so if you want that bssossapp01 localns1.fion.co.in is resolved by others, you need to add an entry for it in the zone file.

2. Yes, it doesn't matter if the email address is not-existent
But it's better to give a real email address, as this is where a notification will be sent if something goes wrong.

3. Again as above it doesn't matter if the MX host is existent. In fact you don't even need to have a MX record.
It is only needed if you want to supply a mail server for the domain in question.

I really wanted to whole-heartedly thank you for the updates.