Clients get wrong DNS

[Warrender6]

Server

• FOG Version:6054
• OS: Ubuntu 14.04

Client

• Service Version:
• OS: Windows

Description

Hello,
I changed the DNS Server from 172.28.0.248 to 10.66.109.10 in /etc/dhcp/dhcpd.conf on the Fog Server (Fog is DHCP Server as well) and restarted the services and the server. Unfortunately the clients get the old DNS.
On an other fog server (0.32 Ubuntu 12.04) I did the same and everything works fine.
Can you help me please?

[Tom Elliott]

To me this sounds like you have multiple DHCP? I don’t know.

Can you show us a copy of your /etc/dhcp/dhcpd.conf file?

[Quazz]

Afaik, clients will retain old information on Windows until they checkin for a new lease.

[Wayne Workman]

Go over to a computer on that subnet and (assuming windows) run this command: ipconfig /release && ipconfig /renew and then see what DNS address it’s using.

[Tom Elliott]

@Wayne-Workman I think another form to ensure all is routing properly would also work:

ipconfig /flushdns

[Quazz]

@Tom-Elliott This would work only if the DHCP information is correct, I believe.

[Tom Elliott]

@Quazz That’s why it’s suggested as an “additional” step.

[Warrender6]

Thanks for your help!
Here is the config.

The clients are not the problem. I run these commands before I started this thread.

[Quazz]

@Warrender6 This looks like a very old generated file.

At any rate, try adding authoritative; before the subnet declaration.

[Warrender6]

@Quazz
Thanks!
I´m not completely sure what you mean.
Should i edit the file like this?

…
next-server 172.28.0.230;
option domain-name-server 10.66.109.10;

subnet…

[Quazz]

@Warrender6

No, simply add authoritative; there.

[Warrender6]

@Quazz
Should there be a link?

[Quazz]

@Warrender6 …a link? No, it’s a DHCP option…

[Wayne Workman]

@Warrender6 Here’s an example. You should just re-write this whole configuration. ISC-DHCP can support both BIOS and UEFI at the same time, you don’t need to go in there commenting and uncommenting filename lines.
https://wiki.fogproject.org/wiki/index.php?title=BIOS_and_UEFI_Co-Existence#Example_2