I am using Fedora Core 4, with yum 2.4.1. However, it is refusing to "play nice" with my proxy, and I am unable to get any updates. It was working properly until some point during the life of FC3, when it suddenly ceased to work with the proxy, and I switched to apt-rpm, which is unfortunately deprecated, and it is becoming more difficult to find apt-enabled repositories, so it is kind of important that I get this to work. I have proxy environment variables set, and they work perfectly with wget (but not with rpm, so maybe it's a python thing). The proxy server is a Microsoft Proxy Server running Websense. I have no Internet access except through the proxy, which only permits traffic for http:// ftp:// and https:// . In particular, I get DNS information from the proxy server -- "ping" will not resolve a URI to an IP, even though a browser will be able to find that URI using the proxy. I have tried giving explicit IP addresses to yum.repos.d as well (see below for results): Here is my yum.conf (taken from fedorafaq.org, with proxy info added in, since yum seems to ignore the environment variable): # Note: This file is no longer the entire yum configuration # for fedorafaq.org. See http://www.fedorafaq.org/#yumconf # for details on how to set up your system with the new # yum configuration. [main] cachedir=/var/cache/yum debuglevel=2 logfile=/var/log/yum.log pkgpolicy=newest distroverpkg=redhat-release tolerant=1 exactarch=1 obsoletes=1 proxy=http://xxx.xx.xxx.xx:80/ proxy_username=DOMAIN\USERNAME #I have also tried this with double \\ proxy_password=******* # We don't want to gpg-check local, unsigned packages #gpgcheck=1 # Changed this because some mirrors go down and then # re-trying takes forever. retries=1 timeout=10 # PUT YOUR REPOS HERE OR IN separate files named file.repo # in /etc/yum.repos.d The error messages (using yum -d10) are: Yum Version: 2.4.1 COMMAND: yum -d10 Installroot: / Setting up Update Process Setting up repositories Baseurl(s) for repo: ['http://193.1.193.67/pub/fedora/linux/core/updates/4/i386/'] Cannot open/read repomd.xml file for repository: updates-released failure: repodata/repomd.xml from updates-released: [Errno 256] No more mirrors to try. Error: failure: repodata/repomd.xml from updates-released: [Errno 256] No more mirrors to try. Any ideas about how to fix this? Thanks in advance.