yum报错Network is unreachable"&Operation now in progress"

yum update的时候报错，刚开始是这样：

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#7 - “Failed to connect to 2604:1580:fe02:2::10: Network is unreachable”

当我把/etc/sysconfig/network-scripts/ifcfg-ens192里面ipv6相关的全部删掉之后，又出现如下错误：

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was
14: curl#7 - “Failed connect to mirrorlist.centos.org:80; Operation now in progress”

判断为yum的服务源和client连接有问题，于是把源换成了163的，问题解决
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget http://mirrors.163.com/.help/CentOS7-Base-163.repo