DNS Scavenging Issues

Posted on 2009-04-16
Last Modified: 2013-11-25
I have taken over a network that has some DNS issues. Scavenging has not been active in over two years. I know that this needs to be setup on intervals to automatically run but the issue I am having is that this doesn't seem to do anything about the old host A files that already exist for machines that are long  gone. On average each server on this network has 3 to 4 host A files attached to its ip address. I am very new to DNS so I am not quite sure how to deal with this issue? I can clean up the servers easily enough because their number is limited but i have 4000 plus clients that makes it unrealistic to try to fix the issue completely by hand.

I am sure there is a quick and dirty way to take care of this and any help would be great! I may just not be using scavenging correctly?
Question by:Diesel79
    LVL 70

    Expert Comment

    by:Chris Dent


    The first thing you have to know about Scavenging is that it requires a fair bit of patience. When you first set the Aging intervals and enable a zone for Scavenging it places a lock on the zone preventing anything from being Scavenged for a full pass of the Refresh Interval.

    When did you enable Scavenging? And what Aging Intervals did you apply?

    LVL 5

    Author Comment

    It has not actually been set yet. I was going to do something like a 15 day expiration with a 20 deletion? Obviously this has ran like it is for 2 years so i figured that interval would be more than enough. I had it set for a bit but the manual scavenge did nothing to help the issue i was having and I am not really familiar enough with this process to be comfortable with just letting it run and "see what it does". Basically your saying not to worry about manually executing one, just set the intervals and let it run and it will eventually clean up these old host A files? I didnt think it was working properly because the manual scavenge left them in place?
    LVL 70

    Accepted Solution


    If you're not sure what each of the values represents and want to understand how it fits together you might find this useful from the MS networking team:

    Once it's running Scavenging can be happily ignored, it just sits in the background and gets on with it.

    I also have some scripts that can be used to report on the state of records in a zone and their associated time stamps. I wrote them to help evaluate the impact of enabling Scavenging on a zone. Would they be any use to you?

    LVL 5

    Author Closing Comment

    The link provided actually worked out great. I dont believe i will need the scripts you offered at this time but if i find out differently i will contact you. Thanks for you help!

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