ConfigMgr: Unknown Host (gethostbyname failed) ApplyOperatingSystem

Recently I saw a ConfigMgr client machine that failed half way through the Task Sequence with the following errors in the SMSTS.log file:

– unknown host (gethostbyname failed) ApplyOperatingSystem
– sending with winhttp failed; 80072ee7

In this case the DHCP lease time was so short that the machine lost it’s lease before the build finished. Increasing the DHCP lease time resolved the issue.

I believe there may be a few different reasons for this particular error message. If I find any more I will update this blog post. Similarly, if you are aware of any other causes of this issue please comment below.