Proxy

What’s a Proxy

The IISER network is a bit different than your usual home/WiFi network. Along with connecting to the WiFi with the WiFi key provided by the Computer Center, you need to also set a setting known as the proxy server.

The proxy server basically acts as an intermediate hop before your data reaches the internet. You can’t bypass the proxy server unless you use a VPN. We need to tell applications which proxy server to use.

The proxy settings

ip:
    nkn1: 172.16.2.250
    bsnl1: 172.16.2.251
    bsnl2: 172.16.2.252
    nkn2: 172.16.2.253
port: 3128
url: http://ip:port/

Note that the institute doesn’t have an HTTPS proxy. Thus, for both HTTP and HTTPS proxy settings, use http://ip:port/.

Setting the proxy url

Windows

For GUI Windows applications, open Settings, search for Proxy and set proxy. Follow this

If in case you are unable to connect despite changing the proxy, try the restart-every-layer-method. Try restarting the application/browser. Then try signing out and signing back in (not just locking). Then try restarting the computer. Or you know what? Just restart the computer. It generally works.

Linux

Global

The method is largely similar to the windows way. Open settings, search for Proxy and set proxy.

Instructions for GNOME and KDE. If you use the default DE of Ubuntu, you are probably using GNOME.

If you aren’t using a DE, but rather relying on a WM like i3, then you will also need to set the environment variables in /etc/environment, and log out and log back in every time you need to change the proxy settings, or at least stop the WM, run source /etc/environment and start the WM again. If this gets annoying, check out the Expert Tips sectionThis is because all children processes use the same proxy settings as the parent, and changing the proxy settings isn’t enough to change your WM’s environment variables. For a much more detailed explanation and Tips and Tricks, see the archwiki page on proxies. Read it, its useful.

Shell

Almost all Linux applications, especially command line applications use the following envars. Simply paste this in your .bashrc or equivalent, making sure to replace ip and port.

export http_proxy="http://ip:port/"
export ftp_proxy="ftp://ip:port/"
export rsync_proxy="rsync://ip:port/"
export no_proxy="localhost,ip/32,192.168.1.1/32,::1,*.local,.ts.net"
export HTTP_PROXY="http://ip:port/"
export FTP_PROXY="ftp://ip:port/"
export RSYNC_PROXY="rsync://ip:port/"
export NO_PROXY="localhost,ip/32,192.168.1.1/32,::1,*.local"
export https_proxy="http://ip:port/"
export HTTPS_PROXY="http://ip:port/"

Final thoughts

Setting the proxy settings via Settings and the envars should generally be enough for most applications. Some applications, notably, all browsers and Zoom, have an in-app way to set the proxy too.

Specific Applications

This should only be used if previous methods fail.

Conda

Write the following to ~/.condarc. On windows, this would be C:/Users/yourname/.condarc.

channels:
- defaults

# Show channel URLs when displaying what is going to be downloaded and
# in 'conda list'. The default is False.
show_channel_urls: True
allow_other_channels: True

proxy_servers:
    http: http://ip:port
    https: http://ip:port

ssl_verify: False

pip

Follow one of these

Julia

Add these lines to ~/.julia/config/startup.jl, which will execute on each new Julia session:

ENV["HTTP_PROXY"] = "http://ip:port"
ENV["HTTPS_PROXY"] = "http://ip:port"

NPM

Write this to ~/.npmrc

strict-ssl=false
proxy=http://127.0.0.1:8888/
https-proxy=http://127.0.0.1:8888/

Expert Tips

Double Proxy

How to cut a diamond? With a diamond. How to fix most proxy problems? With another proxy. Set up a local transparent proxy server at 127.0.0.1:8888, and point everything at it. Then set the upstream proxy of your proxy server as the IISER server. Most transparent proxies allow you to hot change the upstream. Thus, you can change/turn off the IISER proxy without having to change app settings. One such server is tinyproxy.

Port 8888
Listen 127.0.0.1
Timeout 600
Allow 127.0.0.1
Upstream http 172.16.2.250:3128

Sshutling through space

Some limitations of the proxy server, particularly blocked email ports can be overcome by tcp-over-ssh tunnelling. Use sshutle and ssh to a server that sits outside the institute network.