centos6.8服务器设置防火墙之后不能下载mysql

配置完了iptables，开放了22端口留着ssh用，但是当我使用yum -y install mysql mysql-server mysql-devel命令安装mysql时报如下的错误，求大神指导
Error Downloading Packages:
mysql-devel-5.1.73-8.el6_8.x86_64: failure: Packages/mysql-devel-5.1.73-8.el6_8.x86_64.rpm from base: [Errno 256] No more mirrors to try.
mysql-5.1.73-8.el6_8.x86_64: failure: Packages/mysql-5.1.73-8.el6_8.x86_64.rpm from base: [Errno 256] No more mirrors to try.
mysql-server-5.1.73-8.el6_8.x86_64: failure: Packages/mysql-server-5.1.73-8.el6_8.x86_64.rpm from base: [Errno 256] No more mirrors to try.
mysql-libs-5.1.73-8.el6_8.x86_64: failure: Packages/mysql-libs-5.1.73-8.el6_8.x86_64.rpm from base: [Errno 256] No more mirrors to try.
perl-DBD-MySQL-4.013-3.el6.x86_64: failure: Packages/perl-DBD-MySQL-4.013-3.el6.x86_64.rpm from base: [Errno 256] No more mirrors to try.