DHCP server constantly gives out wrong IP addresses despite reservations

Zorlin commented 9 months ago

this is driving me absolutely batty.

I create a new host, as a DHCP static reservation based on its MAC address
I boot that host
It gets the right IP address
I come back minute later
There are TWO DHCP leases, one for the right IP and one for the wrong IP
Resolving this situation involves staring at the moon and the stars and doing a dance and removing all the records and setting everything back up again 3 times until it finally consistently works
Rinse and repeat

Please fix this! It's a critical bug that stops me from using Technitium effectively...

Zorlin commented 9 months ago

Details: Technitium Version 11.4.1, Ubuntu 22.04. Everything else works perfectly :(

Zorlin commented 9 months ago

Maybe part of it is that when I go to create the record, I'm using Proxmox style MAC addresses (0F:FF:CC) that get converted to a format like 4E-90-67-0B-19-CD - perhaps as part of that conversion it doesn't properly set the record somewhere?

ShreyasZare commented 9 months ago

Thanks for the post. This is a know issue which you can read about here to know how to fix it.

Let me know if that worked.

Zorlin commented 9 months ago

Thanks for the post. This is a know issue which you can read about here to know how to fix it.

Let me know if that worked.

Huh! Okay, so it's just terrible dhcp clients being terrible. :) I'll test out the fix, thank you!

ShreyasZare commented 9 months ago

Thanks for the post. This is a know issue which you can read about here to know how to fix it. Let me know if that worked.

Huh! Okay, so it's just terrible dhcp clients being terrible. :) I'll test out the fix, thank you!

Ya, its kind of common issue with clients like Ubuntu as you can see here. The issue comes since the client resets its client-identifier for some reasons causing the DHCP server to think that its a different client so cannot give it the existing non-expired lease.

Zorlin commented 9 months ago

Ah, these are freshly deployed machines, and the deployment process sees them as different clientIDs (or rather the deployment process uses MAC for DHCP)

So that makes sense

On Sat, Sep 23, 2023, 8:05 PM Shreyas Zare @.***> wrote:

Thanks for the post. This is a know issue which you can read about here https://github.com/TechnitiumSoftware/DnsServer/issues/606 to know how to fix it. Let me know if that worked.

Huh! Okay, so it's just terrible dhcp clients being terrible. :) I'll test out the fix, thank you!

Ya, its kind of common issue with clients like Ubuntu as you can see here https://superuser.com/questions/1338510/wrong-ip-address-from-dhcp-client-on-ubuntu-18-04. The issue comes since the client resets its client-identifier for some reasons causing the DHCP server to think that its a different client so cannot give it the existing non-expired lease.

— Reply to this email directly, view it on GitHub https://github.com/TechnitiumSoftware/DnsServer/issues/740#issuecomment-1732294221, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAKONLG45F73QE3EBV6E2WDX33F7RANCNFSM6AAAAAA5DXEELQ . You are receiving this because you modified the open/close state.Message ID: @.***>

TechnitiumSoftware / DnsServer

DHCP server constantly gives out wrong IP addresses despite reservations #740