RDNS on Private Network? 1

[monsterjta]

Can anyone give me a reason why an organization would have reverse DNS records for internal use? I see good reason for public RDNS records for email...but not sure why it one would have any internal.

Thanks for the feedback!

 

[ShackDaddy]

It's so that internal network scanning tools are more easily able to resolve hostnames from IPs and label what they come across. It's fairly common. It actually makes things a lot more tidy in a large network.

Best is when it's automated. Many dynamic DNS systems automatically generate PTR records.

ShackDaddy

 

[monsterjta]

Thanks ShackDaddy. So, I have multiple private networks within my company and the majority of these were inhereted. I've noticed that some of these domains/networks have Reverse DNS lookups configured for other internal networks, but some do not. For practical reasons, other than network scanning tools, is there any other real need for these reverse lookup entries to be there?

Here's an example:

These different networks have their own Exchange servers. If I attempt to send email from one internal domain to another, are we utilizing these RDNS records?

Thanks for the feedback!

 

[ShackDaddy]

No, you're not using the RDNS entries for internal Exchange transactions, as those are done via RPC on a name, not IP basis. RNDS (in the Exchange context) is usually only used with certain anti-spam measures on the public SMTP network.

I wouldn't dismantle the existing RDNS structure unless you are actually re-ip'ing your subnets, but aside from the considerations I mentioned above, there aren't driving needs to get the whole enterprise RDNS'd.

I'm open to alternate opinions on this.

ShackDaddy

 

[ShackDaddy]

I forgot to mention: tracert and ping are tools that use RDNS, but their essential functionality isn't particularly limited by lack of those records.

ShackDaddy

 

[monsterjta]

Thanks, ShackDaddy, for your input.

I didn't realize that ping or tracert made use of RDNS at all. That's interesting! I've recently been handling all the DNS related duties at my company, and have been through a bit of a learning curve as far as email and how it relies on RDNS entries. This prompted me to research more on the subject of RDNS.

I don't plan on dismantling the existing RDNS, as I don't really care about these environments per se. I have been tasked to implement a new enterprise environment with this hosting company, and all domains will soon be consolidated into one ROOT and multiple children.

Cheers!