DNS Server with wrong records

[fooby]

Hi all

 

(have searched - cant find)

 

We are experiencing a weird problem where DNS records do not match PC's, an example of which is PC-01 resolves to 1.2.3.4 and PC-02 resolves to 1.2.3.4 (example addresses) there are also problems where PC-03 resolves to an IP address somewhere else.

 

We are noticing this more with classroom management systems, where i monitor in a room, say ROOM1 and the pc are sequentially numbered ROOM1-01 -02 -03 etc some of these machines for example ROOM1-08 will resolve the wrong address and actually show me ROOM2-24.

 

Im reasonably sure its my DNS servers, so is there a way to safely wipe all the computer records so that they can be re created correctly? Has anyone else had weird issues like this?

 

I think all I would need to do is wipe all the A records for the pc's but i dont want to trash my domain.

 

any help would be appreciated

 

fooby

[Geoff]

Enable scavenging.

[fooby]

I had thought I had done that, I will check over all the settings, as you are correct, scavenging should have fixed this.

 

fooby

[Geoff]

Your scavenging timeouts and dhcp lease times are probably different.

[rob101]

Should they be the same Geoff

[Geoff]

Yes. If your scavanging time is longer than your leases then you'll get duplicate records. If it's shorter, you'll lose active records.

[bizzel]

Do they have to be the same even if dhcp is updating dns? Because our dhcp lease time is one day and scavenging is every 7, however the dhcp server is set to update / remove dns records when it removes leases. I did find over 15 duplicate records in dns last night though...

[bizzel]

The RM tech sounded genuinely terrified when I told him our lease time was 1 day. I'm not sure who set that but it's now 1 week, same as the scavenge interval.

[Geoff]

If machines crash, or are taken off the network never to return, you can get duplicates that way.

[fooby]

Yep

 

We have done that a few times :-S

 

fooby

[fooby]

Last scavenge I did, scavenged 250 ish records....I figure that is bad :S

 

fooby

[djm968]

Have you ghosted anything recently?

[fooby]

Yep.

Loads.

 

fooby

[djm968]

That could explain why you had so many strange DNS records.