I have weird problem. We have two Mcafee Web Gateways in load-balancing mode and last Tuesday I tried to update both nodes from 8.1.1 version to 8.1.5. The 2nd node updated without a problem. But 1st (main) node was unable to update due to problems accessing the update files. I checked the logs and noticed when the proxy connected to various mirrors, it added the asc extension to the file it wanted to download. Because of that it couldn't find the file on none of the servers.
Here is a part of the log, where you can see the problem:
MWG wants to download a file called repomd.xml, but it is not found because it adds an asc axtension to it (that kind of file doesn't exist on any of the mirrors (it only exists without the asc extension))