I'm trying to instal Krita on Linux Ubuntu 16.4 by following this: sudo add-apt-repository ppa:kubuntu-ppa/backports sudo apt-get update sudo apt-get install krita    I'm getting this when I try second command (for update):    Err:1 http://rs.archive.ubuntu.com/ubuntu xenial InRelease                                 Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outErr:2 http://rs.archive.ubuntu.com/ubuntu  xenial-backports InRelease                   Unable to connect to 172.16.0.3:8080:Err:3  http://rs.archive.ubuntu.com/ubuntu  xenial-updates InRelease                    Unable to connect to 172.16.0.3:8080:Err:4 http://archive.canonical.com/ubuntu  xenial InRelease                               Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outErr:5 http://dl.google.com/linux/chrome/deb stable InRelease                              Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outErr:6 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu xenial InRelease                Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outErr:7  http://security.ubuntu.com/ubuntu xenial-security InRelease                          Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outReading package lists... Done             W: Failed to fetch  http://rs.archive.ubuntu.com/ubuntu/dists/xenial/InRelease   Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outW: Failed to fetch  http://rs.archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease  Unable to connect to 172.16.0.3:8080:W: Failed to fetch   http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease  Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outW: Failed to http://archive.canonical.com/ubuntu/dists/xenial/InRelease  Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outW: Failed to fetch http://rs.archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease  Unable to connect to 172.16.0.3:8080:W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/InRelease   Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outW: Failed to fetch http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/dists/xenial/InRelease Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed outW: Some index files failed to download. They have been ignored, or old ones used instead.-I'm not using proxy -The first command also doesn't work:gpg: keyserver receive failed: keyserver error-The third command too, but I won't type anything about third, because I think the main problem is:Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed out-I tried this (so I think a firewall is not problem):sudo ufw disableWhat should I do to be able to update OS, and to be able to install Krita (or any other application)? 
Could not connect to 172.16.0.3:8080 (172.16.0.3), connection timed out
ubuntu;networking;apt