Sunday, 2 July 2017

Ubuntu DNS host resolution issue fixed

Unknown host? what why?

The other day I moved from static IP's to DHCP in my VirtualBox lab and once I did that I found an issue that perhaps others are facing.

When the dynamically assigned DNS was able to resolve external domains such as google etc, I was not able to resolve local ones.

The cause of this issue is the /etc/nsswitch.conf and the line hosts.  If you look closely you can see that the dns is after the not found return, now you might be asking how is this working for google then if dns is not used, well that would be the power of mdns and since my dns wasn't supporting mdns it failed.

Original
hosts:          files mdns4_minimal [NOTFOUND=return] dns

Fixed
hosts:          files dns mdns4_minimal [NOTFOUND=return]




So I moved the dns to the second entry of the line leaving everything else the same and poof like magic problem solved.

Wednesday, 10 May 2017

Restoring the Windows Installer

If you didn't know this already is a bad idea to delete files from the windows installer folder.
The reason for this is when applying windows updates window will often look to compare the previous version and if those files are missing the patch will fail to install.

Chances are you know this already if you are reading this.

Now the question is how can you fix it... well I'm here to tell you there is no easy way.
you will need to download all the install media and extract all the service packs and hotfixes that are missing, this is not so hard.

then you need to copy the correct one into the windows installer folder with the right name.
This is where a PowerShell script that from Ahmad Adel Gad might just save you allot of time.
https://gallery.technet.microsoft.com/scriptcenter/Restore-the-Missing-d11de3a1

This will tell you what package are missing and when pointed to the media copy it to the Windows installer folder for you with the correct names.