https://blog.gongquiz.com/2021/10/13/%ed%94%84%eb%a1%9d%ec%8b%9c-%ec%84%9c%eb%b2%84%ec%9d%98-%ec%9d%bc%ec%a2%85%ec%9d%b8-squid%ec%97%90-%eb%8c%80%ed%95%9c-%ec%84%a4%eb%aa%85%ec%9c%bc%eb%a1%9c-%ed%8b%80%eb%a6%b0-%ea%b2%83%ec%9d%80/