On 05/01/2018 11:26 AM, Marius Rometsch wrote:
> Hello dear SL Users,
> I was directed here from the scientificlinuxforum.org because I seem to have encountered unusual behavior of yum and SL.
> I switched from OpenSUSE to SL7 yesterday and while setting it up, yum could not install or update any packages.
> Whenever i try to install or update I get the following errors: https://pastebin.com/UqKyKANq
> TL;DR: I get back 404 for every repo
> I tried:
> Adding 3rd party repos
> Changing DNS configuration
> cleaning yum
> 
> This is the Link to the original forum post I created with all terminal responeses:
> https://scientificlinuxforum.org/index.php?showtopic=3740
> 
> Please ask me for whatever information you might need.
> 
> Info:
> -Operating System: Scientific Linux 7.4 (Nitrogen)
> -CPE OS Name: cpe:/o:scientificlinux:scientificlinux:7.4:GA
> -Kernel: Linux 3.10.0-693.el7.x86_64
> -Architecture: x86-64
> Everything is freshly installed.
>   
> I am really out of options here. It would be great if someone could help me fiigure this out.
> Thank you in advance and best regards
> Marius Rometsch
> 

A 404 is an active rejection by the far end.  What does your network 
configuration look like?  It could be a firewall/proxy server in between 
preventing you from reaching the destination(s).  Can you access the 
URLs in firefox or with wget?