DHCP release after FOG menu exit

[Aki Heikkinen]

Hello,

How you can release DHCP lease when FOG boot menu exits?

PXE based lease is just computers MAC address. After W10 1809 starts up it happily accepts the existing lease but without updating hostname in DHCP server to computername.domain and thus DNS records are not set correctly.

Or am I missing something else here?

[Aki Heikkinen]

DHCP to DNS dynamic updates are of course enabled.

[Quazz]

I think adding dhclient -r to /images/postdownloadscripts/fog.postdownload might work.

[Aki Heikkinen]

@Quazz said in DHCP release after FOG menu exit:

og.postdownload

Isn’t that launched only after image deployment?

[george1421]

@Aki-Heikkinen What dhcp server are you using?

Is the issue that the dhcp name is wrong, or is it the dns name is wrong? After the system is renamed and rebooted, does the dhcp name still stay the old system name?

The issue with releasing dhcp should be already addressed “during imaging”. If you look at this website: https://github.com/FOGProject/fos/blob/master/Buildroot/board/FOG/FOS/rootfs_overlay/etc/init.d/K40network This is the network shutdown script for FOG.

You will see at line 9 it releases dhcp with
/sbin/udhcpc -i $iface -R

Upon the first boot of Windows 10 while Windows Setup is running, the system is given a random name by WinSetup/OOBE. Once OOBE is done and the FOG client is restarted, the fog client will rename the system and then reboot. Once WinSetup starts then FOG Imaging is not involved other than the FOG Client. IMO this is a windows issue if the name sticking in dhcp is this windows made up initial name and not its real system name. But again without knowing all of the details I can only guess.

[george1421]

Well if I reread your post through a different lens…

When you pxe boot through the fog iPXE boot menu and let the default “Boot to hard drive” menu happen, when windows starts the iPXE dhcp name is still in place and windows is happy to just use that lease. If this is the case then iPXE might not be releasing the dhcp lease when it boots from the hard drive. In this case its not clear who is at fault (iPXE or Windows for just reusing what was there)?