执行 kubeadm join 192.168.31.220:6443 --token 2fn4t4.syeegrav0nadt9mh --discovery-token-ca-cert-hash sha256:df5eee**********************************2e6e653aa83ea8c32 报如下错误

error execution phase preflight: [preflight] Some fatal errors occurred:
        [ERROR FileContent--proc-sys-net-bridge-bridge-nf-call-iptables]: /proc/sys/net/bridge/bridge-nf-call-iptables does not exist
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

解决办法

在/etc/sysctl.conf中添加：

net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1

执行sysctl -p 

如果出现 缺少文件的现象

sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-ip6tables: 没有那个文件或目录
sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-iptables: 没有那个文件或目录

 这是因为之前配置的br_netfilter没有启动

#驱动加载

modprobe br_netfilter

bridge