https://blog.gongquiz.com/2024/04/20/ip-%ed%94%84%eb%a1%9c%ed%86%a0%ec%bd%9c%ec%9d%98-%ed%97%a4%eb%8d%94-%ec%b2%b4%ed%81%ac%ec%84%acchecksum%ec%97%90-%eb%8c%80%ed%95%9c-%ec%84%a4%eb%aa%85-%ec%a4%91-%ec%98%ac%eb%b0%94%eb%a5%b8-%ea%b2%83/