Ubuntu on 菜鸟程序员

gdm3和lightdm切换

Mon, 01 Jan 0001 00:00:00 +0000

# 切换 gdm3
sudo dpkg-reconfigure gdm3

# 切换 lightdm
sudo dpkg-reconfigure lightdm

netplan

Mon, 01 Jan 0001 00:00:00 +0000

在 Ubuntu20.04 版本中使用 netplan 管理网络
在安装好的 Ubuntu20.04 中没有 networking 和 NetworkManage 服务
netplan 配置文件：/etc/netplan/*.yaml ，文件名每个不一样
netplan 说明文件: /usr/share/doc/netplan/example/ 目录下，在该目录下有各种样例文件，可以提供帮助

Ubuntu桌面版设置随机Mac地址

Mon, 01 Jan 0001 00:00:00 +0000

首先右键单击network-manager管理工具，点左键 Edit Connections
点选要配置的连接，点下面的齿轮
红框位置选随机，保存即可

报错处理

Mon, 01 Jan 0001 00:00:00 +0000

由于没有公钥，无法验证下列签名

W: GPG 错误：http://ppa.launchpad.net precise Release: 由于没有公钥，无法验证下列签名： NO_PUBKEY 6AF0E1940624A220

W: 无法下载 bzip2:/var/lib/apt/lists/partial/mirrors.163.com_ubuntu_dists_precise_main_binary-i386_Packages Hash 校验和不符

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6AF0E1940624A220 #此处6AF0E1940624A220需要是错误提示的key

ssh无法连接到外网Linux主机

场景描述：

内网Linux主机ssh连接正常，不能ssh连接外网Linux

telnet 外网IP 22 通，ping命令通

此时可以试试以下方法

koala@koala:~$ ssh root@domain.com
(等待很久)Connection closed by xx.xx.xx.xx port 22

koala@koala:~$ ssh -v root@domain.com
OpenSSH_8.4p1, OpenSSL 1.1.1f 31 Mar 2020
debug1: Reading configuration data /usr/local/etc/ssh_config
debug1: Authenticator provider $SSH_SK_PROVIDER did not resolve; disabling
debug1: Connecting to domain.com [xx.xx.xx.xx] port 22.
debug1: Connection established.
debug1: identity file /home/koala/.ssh/id_rsa type 0
debug1: identity file /home/koala/.ssh/id_rsa-cert type -1
debug1: identity file /home/koala/.ssh/id_dsa type -1
debug1: identity file /home/koala/.ssh/id_dsa-cert type -1
debug1: identity file /home/koala/.ssh/id_ecdsa type -1
debug1: identity file /home/koala/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/koala/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/koala/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/koala/.ssh/id_ed25519 type -1
debug1: identity file /home/koala/.ssh/id_ed25519-cert type -1
debug1: identity file /home/koala/.ssh/id_ed25519_sk type -1
debug1: identity file /home/koala/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/koala/.ssh/id_xmss type -1
debug1: identity file /home/koala/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH_7.0*,OpenSSH_7.1*,OpenSSH_7.2*,OpenSSH_7.3*,OpenSSH_7.4*,OpenSSH_7.5*,OpenSSH_7.6*,OpenSSH_7.7* compat 0x04000002
debug1: Authenticating to domain.com:22 as 'root'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
Connection closed by xx.xx.xx.xx port 22

此时查看本机mtu值

替换清华源

Mon, 01 Jan 0001 00:00:00 +0000

Ubuntu24.04 以后默认源在 /etc/apt/sources.list.d/ubuntu.list 文件里

https://mirrors4.tuna.tsinghua.edu.cn/help/ubuntu/

方式一 sed替换

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak 
sudo sed -i "s@http://.*archive.ubuntu.com@https://mirrors.tuna.tsinghua.edu.cn@g" /etc/apt/sources.list
sudo sed -i "s@http://.*security.ubuntu.com@https://mirrors.tuna.tsinghua.edu.cn@g" /etc/apt/sources.list
sudo apt update && sudo apt full-upgrade

方式二配置文件替换

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak
 
 echo "正在替换为清华源..."
 cat << EOF | sudo tee /etc/apt/sources.list
# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse

# 以下安全更新软件源包含了官方源与镜像站配置，如有需要可自行修改注释切换
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse

# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
EOF
 
 echo "更新..."
 sudo apt-get update

Ubuntu on 菜鸟程序员

gdm3和lightdm切换

netplan

Ubuntu桌面版设置随机Mac地址

报错处理

由于没有公钥，无法验证下列签名

ssh无法连接到外网Linux主机

替换清华源

方式一 sed替换

方式二 配置文件替换

方式二配置文件替换