When you are behind HTTP proxy, you need to configure proxy settings for your applications in one way or another. Typically you define http_proxy environment variable pointing to your proxy, so that all HTTP requests go through the proxy. But what if you want to bypass HTTP proxy for specific destination web servers? That's when you need to configure HTTP proxy exceptions.
On Linux, you can define HTTP proxy exceptions via "no_proxy" environment variable. In "no_proxy" variable, you specify a list of domain names or IP addresses for which HTTP proxy should not be used. Along with domain names or IP addresses, you can also specify port number if necessary.
If you would like to define HTTP proxy exceptions system wide, do the following.
On Ubuntu, Debian or Mint:
http_proxy="http://proxy.com:8000" no_proxy="127.0.0.1, localhost, *.cnn.com, 192.168.1.10, domain.com:8080"
On CentOS, Fedora or RHEL:
export http_proxy="http://proxy.com:8000" export no_proxy="127.0.0.1, localhost, *.cnn.com, 192.168.1.10, domain.com:8080"
The above example means that if you are reaching local host (e.g., 127.0.0.1, localhost), *.cnn.com, domain.com:8080, or a host with IP address 192.168.1.10, you will not use HTTP proxy. For all other destinations, you will use the designated HTTP proxy (proxy.com:8000).
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