DHCP/DNS Issues

[Gongalong]

Hi folks,

 

I inherited the DHCP/DNS setup here, and for the most part it's been fine. We have a single (Windows 2019) DHCP server, and two DNS servers.

 

The only issue I had previously was that DHCP didn't have any credentials to update DNS, which caused issues updating SIMS clients, but that's all fixed now.

 

I've just spotted an issue today though that a lease was given out to a laptop, but on the DHCP server the lease was shown as given to another (desktop) PC, and isn't expiring until the 22nd December. This caused issues with deploying some software.

 

Questions:

 

1. Is an 8 day lease time fairly standard? Perhaps I should be reducing this to say 1 day. We haven't hit the scope limit as far as I'm aware.

2. Should I enable Name Protection? This is currently disabled, although I don't really see this as the cause of why a current lease was given out to a different computer.

3. How do I troubleshoot how the laptop was given a lease that was already showing for this different desktop PC?

 

Thanks

[TwistedHelixis]

Do you have DNS Scavenging setup?

 

Think our lease time is set at 4 days.

[Gongalong]

I've checked and it's not enabled.

 

For the two PCs in question I did refresh DHCP and DNS, and could see that both showed a record for a particular desktop, but a laptop I was trying to deploy software to had the IP address. I checked IPCONFIG on the laptop and it showed as having received a DHCP lease from the correct server. I didn't check at the time whether the desktop was still switched on, but its lease was valid to something like 22nd Dec.