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Bourne
Asked: 2011-08-05 15:20:03 +0800 CST

Why are these reverse lookup DNS containers grayed out?

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We had a single reverse lookup zone in our 2008 DNS with the name:

220.10.in-addr.arpa (I'll call this the mother zone) which was hosting records from 3 different subzones / child zones:

10.220.0.x, 10.220.1.x and 10.220.2.x.

In trying to separate records of one zone from the others, I created initially two zones, 0.220.10.in-addr.arpa and 1.220.10.in-addr.arpa that are replicating to all DNS servers in the domain. At first, these zones appeared at the same level as the 220.10.in-addr.arpa but then after a while two grayed out containers corresponding to each child zone showed up underneath the mother zone in addition to the individual ones I created.

enter image description here

Why are these containers grayed out and why did they not show up at the beginning? Does grayed out mean that they are delegated?

Thank you.

windows-server-2008 domain-name-system

2 Answers

  1. Best Answer

    When you create an rDNS zone for the parent network 10.220 the DNS service will automatically create a child zone under the parent zone for each subnet of the parent zone (network) that it discovers when clients from those subnets register their PTR records. You've wound up with delegated zones under the parent zone because the DNS service has discovered that you've already created zones for those subnets so it creates a delegated zone under the parent zone that points to your manually created zones.

    The way I prefer to do it is to create a rDNS zone for the parent network and let the DNS service create the child zones when clients from those subnets register their PTR records. This is the opposite of what you've done so let me clarify:

    If you want to manually create zones for each subnet then don't create a zone for the parent network (10.220).

    If you want the DNS server to create the child zones for the subnets that fall under the 10.220 network/DNS zone then delete the 10.220.0 and 10.220.1 zones that you manually created.

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  2. Yeah, those should be delegations - if you click on them, the only records present are of type NS, correct?

    They were likely auto-magically generated by the DNS server, as it knew it had something screwed up hierarchically.

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