ubuntu22.04通过netplan配置网络
1.以前的网络配置
ubuntu系统里通常在/etc/network/interfaces里配置好IP等信息
interfaces文件配置内容大概如下：
auto enp0s3
iface enp0s3 inet static
address 10.0.2.15
netmask 255.255.255.0
gateway 10.0.2.1
dns-nameservers 218.85.157.99
保存关闭后，使用sudo systemctl restart networking或sudo /etc/init.d/networking restart重启网络，然后新的配置就会生效。
2.netplan工具
但是现在从ubuntu18.04开始，开始使用netplan工具来配置IP了，而不是使用interfaces文件和/etc/init.d/networking脚本。
如果执行以上2条命令，结果如下：
ubuntu@ubuntu:~$ sudo systemctl restart networking
Failed to restart networking.service: Unit networking.service not found.
ubuntu@ubuntu:~$ sudo /etc/init.d/networking restart
[sudo] password for ubuntu:
sudo: /etc/init.d/networking: command not found
查看ubuntu版本
ubuntu@ubuntu:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.3 LTS
Release: 22.04
Codename: jammy
netplan工具默认已经安装
ubuntu@ubuntu:~$ netplan
You need to specify a command
usage: /usr/sbin/netplan [-h] [--debug] ...
Network configuration in YAML
options:
-h, --help show this help message and exit
--debug Enable debug messages
Available commands:
help Show this help message
apply Apply current netplan config to running system
generate Generate backend specific configuration files from /etc/netplan/*.yaml
get Get a setting by specifying a nested key like "ethernets.eth0.addresses", or "all"
info Show available features
ip Retrieve IP information from the system
set Add new setting by specifying a dotted key=value pair like ethernets.eth0.dhcp4=true
rebind Rebind SR-IOV virtual functions of given physical functions to their driver
try Try to apply a new netplan config to running system, with automatic rollback
2.1netplan的安装
题外话，由于我切换了apt源，并且更新了软件列表，安装了Python3-pip，导致netplan工具消失（具体安装过程我也没仔细看），
重新安装netplan.io报错：
netplan.io : Depends: libnetplan0 (= 0.104-0ubuntu2~20.04.2) but 0.105-0ubuntu2~22.04.3 is to be installed
按照如下步骤重新安装即可：
apt install libudev1=245.4-4ubuntu3.22
apt install udev
apt install network-manager
apt install libnetplan0=0.104-0ubuntu2~20.04.2
apt install netplan.io
2.2配置静态IP
netplan工具通过.yaml配置文件对网卡进行配置，在/etc/netplan/目录下存在.yaml文件，可以先备份下原有文件再做修改，或者再新建一个yaml文件用于配置。
该文件只有root用户有write权限
-rw-r--r-- 1 root root 485 Aug 20 20:54 /etc/netplan/50-cloud-init.yaml
使用sudo命令
sudo nano /etc/netplan/50-cloud-init.yaml
修改文件内容，配置静态IP如下
network:
ethernets:
enp0s3: # 网卡名称
dhcp4: false # 使用静态IP
match:
macaddress: 52:54:00:a5:64:b5
set-name: enp0s3
addresses: [10.0.2.15/24]
#gateway4: 10.0.2.1 `gateway4` has been deprecated
routes: # 配置默认网关
- to: default
via: 10.0.2.1
nameservers: # 配置dns服务器地址
addresses: [10.0.2.1, 218.85.157.99]
version: 2
2.3测试配置
netplan try
该命令验证*.yaml配置文件是否有效
ubuntu@ubuntu:~$ netplan try
/etc/netplan/50-cloud-init.yaml:13:13: Error in network definition: unknown key 'addressed'
addressed: [10.0.2.15/24]
如上，配置文件有问题就会报错。正常可以看到
Press ENTER before the timeout to accept the new configuration
Changes will revert in 103 seconds
Configuration accepted.
配置通过验证了。
2.4应用新的配置
sudo netplan apply
2.5查看配置后的IP信息
ubuntu@ubuntu:~$ ip a
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 52:54:00:a5:64:b5 brd ff:ff:ff:ff:ff:ff
inet 10.0.2.15/24 metric 100 brd 10.0.2.255 scope global dynamic enp0s3
valid_lft 86399sec preferred_lft 86399sec
inet6 fe80::5054:ff:fea5:64b5/64 scope link
valid_lft forever preferred_lft forever
3.临时IP配置
如果网卡还没有配置IP，netplan工具也没有安装，apt install时是没有网络的，可以临时配置IP来解决
##添加临时IP
ip addr add 10.0.2.15/24 dev enp0s3
##添加网关
ip route add default via 10.0.2.1
##up端口
ip link set eno3 up
