topic Re: Duplicate lease on DHCP after rebuilding process in Horizon Desktops and Apps

Duplicate lease on DHCP after rebuilding process

MaorZoh — Wed, 20 Sep 2023 07:38:54 GMT

Hi,

We have some Full-Clone pools, and from time to time we rebuild random machines.

In most cases, the machine is getting a new IP after rebuild but the old lease stays on the DHCP server and additional lease is created with the new IP.

This causing the user to unable to connect to their machines until I manually delete the old lease and wait until the DNS server are updated with the change.

I tried to follow this article but no change.

https://www.mustbegeek.com/configure-dns-dynamic-update-in-windows-dhcp-server

Does anyone have an idea how to solve this?

Thanks.

Re: Duplicate lease on DHCP after rebuilding process

a_p_ — Wed, 20 Sep 2023 17:45:55 GMT

Some thoughts.

The link you posted is about DNS and the DNS record ownership, which is of course important.
However, the issue that you describe is related to the DHCP-Server and the lease time. Depending on how many VMs you rebuild wihin a given time frame, you'll need to have a umber of additional available IP addresses, and make sure that you also reduce the the lease time for the VMs' DHCP scope.

André

Re: Duplicate lease on DHCP after rebuilding process

MaorZoh — Thu, 21 Sep 2023 05:23:33 GMT

Hi André,

Thank you for your reply.

Actually, our DHCP scope is pretty big and there are enough available IP addresses for the machines to acquire.

Lease time is configured for 2 days. I\ll consider reducing it even more.

Re: Duplicate lease on DHCP after rebuilding process

scott28tt — Thu, 21 Sep 2023 05:36:15 GMT

A new MAC address means a new DHCP lease.

I don’t think your issue is “with” Horizon (or the platform on which you are running your VMs), but those network services such as DHCP and DNS.

Re: Duplicate lease on DHCP after rebuilding process

MaorZoh — Thu, 21 Sep 2023 05:47:43 GMT

Hi Scott,

It makes sense, but I partially agree with it because in another environment we have it doesn't happen to us, but only in a specific environment and both communicate with the same DHCP server.

Even with a new MAC address, it should not happen, otherwise especially Instant-Clones would have problems all the time.

I reduced the leas time from 2 days to 4 hours to check if it has a positive effect.

Thanks.