DNS Scavenging - Aarrgghhh!!

[brahma]

Hello All.

 

Sorry for the number of posts I'm putting up - I'm new to this schools network and there are lots of problems!! See previous posts on DNS issues.

 

The problem that I have is multiple records in DNS for the same IP address but with different device names - e.g. I have one IP address that has 6 names associated with it!!

 

I have 4 domain controllers and scavenging is turned on on 2 of the four - at server level (i.e. right click server name, select Ageing and Scavenging). On these two, I've got the default settig of 7 days No-Refresh and Refresh. If I select the domain name from each server (under Forward Lookup Zones, Right Click Properties, Aging), all four are set to scavenge with the default setting of 7 days No-Refresh and Refresh.

 

If I check my DHCP settings, my lease time is set to 14 days. This doesnt seem right - I thought DNS No-Refresh / Refresh days should be about the same as DHCP lease times (8 days I though??)

 

I have manuall selected "Scavenge Stale Resource Records" on my root server and this has done the following:Visisted Zones = 4; Visisted Nodes = 561; Scavenged Nodes = 442; Scavenged Records = 783. Its obviuosly gotten rid of a lot of redundant items, but I still have lots of duplicates!!!

 

Help!! Should I turn scavenging off on all but one DNS Server (my root server) and set DHCP Lease time to 8 days? Or somthing else.

 

Sorry for the long post - but I'm kinda getting frustrated now!!

[Domino]

I was under the impression scavenging had to be enabled on all domain controllers....

[Guest Guest]

You havnt got DHCP enabled on more than 1 DC have you? You can have it on more than 1 but you need to have differant scopes/exclusion ranges.

[brahma]

Only got one DHCP server on the network. Am going to set another one up and disable the scope so I've got something ready for a disaster situation

[contink]

You might want to check that you don't have a WLAN or Switch with DHCP on it that you didn't realise about.

 

Had fun with a netgear WLAN controller that did this without prompting..

[PiqueABoo]

Should I turn scavenging off on all but one DNS Server (my root server) and set DHCP Lease time to 8 days

 

I would. Make sure you've set the scavenging interval via the dns server properties tabs.

 

Also turn on dns advanced view and check those surplus PTR records can be scavenged and have credible timestamps. If they don't you may have to force that via dnscmd.