The Ubuntu PC is behind a proxy server that requires a password. On Windows it automatically uses windows authentication (e.g. with Internet Explorer), or enter it manually (e.g. Avast). I did a search but could not find a similar question to address this issue.
I'm already aware of the global network proxy preferences (System > Preferences > Network Proxy), but it only takes the proxy server and port. This is not a problem with Firefox, because it prompts for the username and password. How do I make this work for Ubuntu's Software Center? It only prompts me for my user password, but the Ubuntu user is not a network user.
Error Detail: W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/maverick/main/source/Sources.gz 407 Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy filter is denied. )
I'm using Ubuntu 10.10, and my Linux skills are somewhat rusty.
EDIT: ddk's answer seems like what I'm looking for, but I cannot seem to get cntlm to work correctly. I followed the configuration steps he provided, and I updated to global network proxy to
localhost:<listen_port> and removed my username and password (under detail). The test command
sudo cntlm -M http://google.com/ passed, but when I test it with Firefox cntlm fails with the error "502 Parent proxy unreachable."
EDIT FIXED: It worked after I rebooted. The restart command
invoke-rc.d cntlm restart does not restart, so the config file is never read.