Add following two lines at the end of file '/etc/bash.bashrc'
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export http_proxy=http://username:password@netmon.iitb.ac.in:80/
export ftp_proxy=http://username:password@netmon.iitb.ac.in:80/
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export http_proxy=http://username:password@netmon.iitb.ac.in:80/
export ftp_proxy=http://username:password@netmon.iitb.ac.in:80/
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