SOA and Name servers -- newbie question.

  • Thread starter Thread starter Martin
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M

Martin

Hi,

I am a little stumped between the relationship between SOA and "Name server"
and would appreciate somebody explaing their involvement in the name
resolution process on the internet. At present my "SOA" and "Name server"
are held with two different entities. (I am not quite sure how this
originally occured.)

I am under the impression that the "SOA" holds the address of my name
server, and my "name server" points to the IP address of my site.

What I am confused about is how a user gets to my site.

I have learnt that when a user types in the browser www.mysite.com a
recursive query takes place first to the root server to establish the
address of the .com server.

I know that somewhere along the line my "name server" will forward the
request on to mysite.com.

However what I am unsure about is the role of my SOA in all of this. Is the
SOA involved in the name resolution process at all OR is the SOA just an
interface through which to change the address that the name server holds and
the "SOA" is not involved in the name resolution process at all.

any help or pointers to articles of interest is appreciated.

Thank you for your time.

martin.
 
In
Martin said:
Hi,

I am a little stumped between the relationship between SOA and "Name
server" and would appreciate somebody explaing their involvement in
the name resolution process on the internet. At present my "SOA" and
"Name server" are held with two different entities. (I am not quite
sure how this originally occured.)

I am under the impression that the "SOA" holds the address of my name
server, and my "name server" points to the IP address of my site.

What I am confused about is how a user gets to my site.

I have learnt that when a user types in the browser www.mysite.com a
recursive query takes place first to the root server to establish the
address of the .com server.

I know that somewhere along the line my "name server" will forward the
request on to mysite.com.

However what I am unsure about is the role of my SOA in all of this.
Is the SOA involved in the name resolution process at all OR is the
SOA just an interface through which to change the address that the
name server holds and the "SOA" is not involved in the name
resolution process at all.

any help or pointers to articles of interest is appreciated.
Click to expand...

The SOA record states the name of the Primary or "Master" name server (Mname
Record), among other things like zone serial, Responsible person (Rname),
Refresh, Retry, Expire time, Minimum TTL for the zone, and TTL for itself.
The record is not really involved in the resolution process, but is used by
DNS servers (both resolving proxy and Secondary DNS) to verify Authority of
the zone.
It is possible for the Mname record to not even have an NS record, in that
case to be proper the Master is hidden from resolving proxy DNS and can only
be contacted by the DNS listed with NS records, which only hold secondary
zones. (do a Google search for Hidden Master DNS)
 
Thanks for the answer.

could I just run one more theory about the SOA server past you please..

so are you saying that if during name the name resolution process the
primary name server is contaced the the resolving proxy does not need to
know or care about the soa record.

however if a seconday server is contacted then the soa server is contacted
first in order to find out the location of the primary name server.

thanks in advance.

martin.
 
In
Martin said:
Thanks for the answer.

could I just run one more theory about the SOA server past you
please..

so are you saying that if during name the name resolution process the
primary name server is contaced the the resolving proxy does not need
to know or care about the soa record.
Click to expand...

If the SOA record is not asked for, it won't be included in the answer.
however if a seconday server is contacted then the soa server is
contacted first in order to find out the location of the primary name
server.
Click to expand...

No, a resolving proxy is only looking for the answer to its query. In simple
terms if the content DNS just happens to be a secondary, the resolving
proxy does not ask "hey, are you a secondary or a primary" it asks "do you
have this name". Whether it is a Primary or a Secondary does not matter.

I'm not sure what you are getting to here, the SOA record has certain data
on it that is for informational and caching purposes only and is not a
required record for general queries. If your query for the SOA record you
should get it, if you don't query for the SOA record you won't. Secondary
DNS servers use the record to tell if the zone they have is still a valid
zone. If the zone is nearing expiration time it has the name of the server
that should have a valid zone, how often to refresh its zone, and how often
to retry if the refresh is not successful.
 
Hi Kevin,

Thank you for your answer.

I now understand alot better although I still need to do a good bit of
reading. :)

cheers

martin.
 
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