DNS not updating from DHCP?

[PrimaryTech]

Hi all,

Whilst looking through a SOLUS 3 issue I've come across a a potential DNS issue. Looking through my A and PTR records I have lots of records for the same IP address. Lots of these records are for machines that we do not have anymore so I'm a little baffled as I'm sure when I set the network up DNS and DHCP were linked. Any ideas on how this can be resolved would be greatfully received, I'm not great with DNS so as dumbed down as possible...

[LukeC]

have you got scavenging enable to clear out records older than a period of time?

[sparkeh]

Yeah sounds like scavenging is not set up

Don't be afraid of DNS Scavenging. Just be patient. - Microsoft Enterprise Networking Team - Site Home - TechNet Blogs

[tmcd35]

If it helps any, I use 8hr timestamps and scavaging. Means we always start with fresh DHCP at the start of each school day

[PrimaryTech]

Looks like the scavenging is enabled on records but not on the zone or the server (See pics). I'm going to follow the instructions in the 'Don't be afraid of DNS scavenging' document, is there anything else I should be wary of? I'll do a system state backup before I start but I'm worried I'm going to remove records for our DC (Also the DHCP and DNS server).

[sparkeh]

No you won't lose anything like static DC records, scavenging only removes expired records.

[PrimaryTech]

So do I need to change any DHCP settings? Currently my DHCP lease time is 8 days and my DNS settings within DHCP are in the pic attached. I'm thinking of keeping the lease time of 8 days and then setting the No Refresh Interval and Refresh to 4 days, does this sound like a good idea? What happens, say, during Christmas when the computers aren't used for 2 weeks? Will my Forward Lookup Zone be bare come January and is this a problem? Sorry for all the questions but I'm wary of anything DNS-related