sudo nano /etc/netplan/01-netcfg.yaml

1.Ubuntu设置静态IP

修改/etc/netplan/01-netcfg.yaml 或其它在/etc/netplan目录下的文件：

sudo vim /etc/netplan/01-netcfg.yaml

修改为：

#root@master:/etc/netplan# cat 50-cloud-init.yaml
# This file is generated from information provided by the datasource.  Changes
# to it will not persist across an instance reboot.  To disable cloud-init's
# network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    ethernets:
        eth0:
            dhcp4: no
            addresses:
              - 172.22.94.87/20
            routes:
              - to: default
                via: 172.22.80.1
            nameservers:
                addresses: [8.8.8.8, 8.8.4.4]
    version: 2

最后运行：

sudo netplan apply

2.Linux设置允许root ssh登陆

ubuntu下载安装ssh:

sudo apt install openssh-server

修改文件：

sudo vim /etc/sshd/ssh_config

添加下面代码：

PermitRootLogin yes

sudo passwd root

重启ssh:

sudo systemctl restart sshd

其它命令

查看tcp拥塞窗口 cwnd:

ss -lni |grep cwnd