We help IT Professionals succeed at work.

Windows 2003 DNS scavenging records

691 Views
Last Modified: 2008-04-24
I am running Windows 2003 SP1 with integrated DNS zones.
I have an issue where Host Records and ptr records are not being scavenged.  I am aware of how to fix, using the gui and dnscmd.  I need to use the /ageallrecords switch.  My question is this, ageallrecords will set todays date/time stamp so that when the next scavenging cycle happens they will be removed (if dns client doesnt update them)  This is fine for dynamic addresses such as clients but how will this setting effect servers with static address?  If I run this command am I going to find all my static addresses removed and in deep water?  Thanks in advance!  
Comment
Watch Question

PberSolutions Architect
CERTIFIED EXPERT

Commented:
You're assumptions are correct

Be careful using /ageallrecords switch.  It does exactly what is says.  It ages all records including static ip addresses.  

Do you have aging and scavenging enabled on your DNS server?  
PberSolutions Architect
CERTIFIED EXPERT

Commented:
You should set your aging to match your DHCP intervals.  

A good guideline is: The no-refresh interval should match or be slightly lower than 50% of your DHCP lease.  The refresh should be the remainer of the lease.

i.e. DHCP lease 4 days
No refresh - 2 days
Refresh - 2 days.

Once aging is set on your zone, enable scavenging on only 1 DNS server (since AD replication will take care of the other DNS server since you mentioned your AD integrated).

Author

Commented:
I thought so.... I am currently using:
No-refresh 3 days
Refresh 1 days
Our DHCP servers are set to release after 3 days but also to release on computer shutdown (set at the DHCP server (option with windows 2000+))

So will static entries use dns client to refresh the lease?  Ie: I have servera with a static host and ptr record to 10.10.0.1, will servera use dnsclient to renew this static record and stop it getting scavenged?
Solutions Architect
CERTIFIED EXPERT
Commented:
This one is on us!
(Get your first solution completely free - no credit card required)
UNLOCK SOLUTION
PberSolutions Architect
CERTIFIED EXPERT

Commented:
You are not alone with this problem.  Many companies see this same issue with DHCP and Dynamic DNS.  Usually they are laptop machines moving around or VPNing into the network.  Properly configured Aging and Scavenging helps most of the issues, but not all.  

Having DHCP update DNS instead of the client via the "Register this connection's addresses in DNS" setting also helps.  When the DHCP lease expires, the DHCP can be configured to remove the DNS entries.  We set this option on the scopes for conference rooms and the VPN subnets.

One word for the wise, don't set aging less than 24 hours.  This will cause scavenging of the domain SRV records which are updated every 24 hours or so.  And as you are probably aware, losing the SRV records is bad.

Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Unlock the solution to this question.
Join our community and discover your potential

Experts Exchange is the only place where you can interact directly with leading experts in the technology field. Become a member today and access the collective knowledge of thousands of technology experts.

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.