Reverse dns question

[mtz_federico]

I have been wondering how does reverse dns and I haven't been able to find anything that answers this so I'm going to ask here.

When I make a reverse dns lookup how does the dns server know where to find (in which authoritative dns) the reverse dns record for that specific ip?

[Oshino Shinobu]

Reverse lookup zones have an address space assigned. It's typically an address that's in the format of x.x.x.in-addr.arpa.

 

These address spaces, like forward lookup zones, have associated name severs and an SOA record. The address spaces are formatted in reverse. So for the address space 192.168.1.x the reverse lookup zone is 1.168.192.in-addr.arpa. 

 

DNS will look at the address and send it to the correct reverse lookup zone based on the which address space it's in, then from there it can go to an associated name server which should have the PTR record. 

 

Apologies for the rubbish redacting of server names (i'm on a laptop with a trackpad and used paint), but here's my DNS at home.

 

 

[mtz_federico]

4 minutes ago, Oshino Shinobu said:

then from there it can go to an associated name server which should have the PTR record. 

how is it associated? from A records pointing to an ip in the same block in which the ip in the reverse dns record is in?

 

What is that app that you are using for dns?

 

thanks for the quick response

[Oshino Shinobu]

1 minute ago, mtz_federico said:

how is it associated? from A records pointing to an ip in the same block in which the ip in the reverse dns record is in?

 

What is that app that you are using for dns?

 

thanks for the quick response

It's associated by PTR records. If you setup the reverse lookup zones prior to adding A records, you can set it up to automatically create the associated PTR record in the correct reverse lookup zone. PTR records are basically the opposite of A records. 

 

That's the DNS Manager from the DNS role on Windows server.