[Last Call] Learn how to a build a cloud-first strategyRegister Now

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 894
  • Last Modified:

Scavenging DNS records

Hi,

We have a lot of old duplicated records and i was going to enable scavenging.

However, having a look at some of the timestamps of the records such as the ones for the Exchange 2003 Cluster, i see that their timestamp is from 2005 (i assume when setup).

If i enabled scavenging would it also wipe out these records?

0
he_who_dares
Asked:
he_who_dares
  • 4
  • 3
1 Solution
 
dhoffman_98Commented:
Only if they are dynamic records.
DNS records that you create manually as static records will not be scavenged.

Here's some good reading:
http://blogs.technet.com/networking/archive/2008/03/19/don-t-be-afraid-of-dns-scavenging-just-be-patient.aspx
0
 
he_who_daresAuthor Commented:
How do you know if they are static or not?

We use dynamic dns and i would imagine those records for the Exchange were dynamically created when it was built..
0
 
dhoffman_98Commented:
Well, if the record is there because the machine joined the domain and registered it's own DNS, then it's dynamic. If you manually went into DNS and created the record, then most likely it's static, especially if you turn off the check box that says to delete the record when it expires.
0
Fill in the form and get your FREE NFR key NOW!

Veeam is happy to provide a FREE NFR server license to certified engineers, trainers, and bloggers.  It allows for the non‑production use of Veeam Agent for Microsoft Windows. This license is valid for five workstations and two servers.

 
he_who_daresAuthor Commented:
Well i imagine the server records were created when joined to the domain yes.

The image below shows the record for one of the exchange cluster nodes.

Does this mean it will get deleted if i run scavenging?
dns.JPG
0
 
dhoffman_98Commented:
Yes. If you turn off that checkbox, then it becomes a static record that will never become stale and will never have to be refreshed by the client.
0
 
he_who_daresAuthor Commented:
so really then its very dangerous to use scanvenging as it could wipe out all your server records?!
0
 
dhoffman_98Commented:
No. Not necessarily. Since the server updates it's record every day anyhow, then the records should always be fresh. Scavenging will only delete records that are old and outdated. The graphic below shows the settings that can be used for scavenging. The default setting of 7 days shows to only delete records that have not been updated within 7 days.

Here is an article from Microsoft that further details the workings behind Dynamic DNS updates from servers. In particular, "By default, Windows XP and Windows Server 2003 reregister their A and PTR resource records every 24 hours regardless of the computer's role."
From: http://support.microsoft.com/kb/816592



Scavenging.jpg
0

Featured Post

 The Evil-ution of Network Security Threats

What are the hacks that forever changed the security industry? To answer that question, we created an exciting new eBook that takes you on a trip through hacking history. It explores the top hacks from the 80s to 2010s, why they mattered, and how the security industry responded.

  • 4
  • 3
Tackle projects and never again get stuck behind a technical roadblock.
Join Now