My company's firewall enforces NTLMv2 proxy authentication, which kinda sucks for some Linux hosts since I can't pass that authentication directly on the command line. Maybe I'm dumb, but every command format I found didn't work. But this did work...
1. Install CNTLM package: apt-get install cntlm
2. Configure username/password in /etc/cntlm.conf.
3. Restart cntlm service: /etc/init.d/cntlm restart
4. Try this format: http_proxy='http://127.0.0.1:3128/' apt-get update
CNTLM does the authentication for you, so you can relax and think about more important things.
NOTES
* Enable remote hosts in cntlm.conf to allow other hosts to use this child proxy.
Linux and NTLMv2 Proxy Authentication
- Details