错误详情：
error: "net.bridge.bridge-nf-call-ip6tables" is an unknown key
error: "net.bridge.bridge-nf-call-iptables" is an unknown key
error: "net.bridge.bridge-nf-call-arptables" is an unknown key
解决方法：
[[email protected] /]# modprobe bridge
[[email protected] /]# lsmod|grep bridge