apt-get unable to connect to repository

[R Ravi Kiran]

Release: Linux Mint 15 "olivia"
Edition: Cinnamon 32-bit & 64-bit
Internet Connected: Yes
Proxy: Yes

When I try installing a software via software Manager or via terminal using apt-get, the command fails citing error 111 - connection refused. I have attached a log file of the details for reference. However, I am able to browse the web via Firefox without any isses. I am able to ping my local network ips seamlessly. The only issues is getting the software centre to work or the terminal commands to connect to software repositories.

When I open the software repository links like 'http://security.ubuntu.com/ubuntu/dists/raring-security/Release.gpg' on the browser, it works as expected and I am taken to appropriate website. I tried to google for solutions but nothing worked for me.

I installed the OS on one machine and then hit upon this issue. Found the same problem even on the live-os. I have been using Ubuntu for a few years now and am quite comfortable with linux operating systems.

[j (j-the-k)]

I do have the same problems.
Internetconnection works except the softwarecenter and apt, because I always get the 111 error. I have tried different repository sources but none worked so far. I'm behind my companie's proxy, maybe this could have to do anything with that, but I have configured the proxy like I did on my Ubuntu machine (which is behind the same proxy) and apt works there.

[j (j-the-k)]

I got everything to work by adding the proxy settings in /etc/environment:

http_proxy="http://myproxy.de:8080/"
https_proxy="https://myproxy.de:8080/"
ftp_proxy="ftp://myproxy.de:8080/"

Strangely the entries in /etc/apt/apt.conf (Acquire::http::proxy "http://myproxy.de:8080/"; ...) and setting the environment variables $http_proxy, $https_proxy, $ftp_proxy did NOT help. Some mechanism seems so look at /etc/environment only (?)