Ubuntu 20.04上搭建vpn服务器

OpenVPN

OpenVPN 是一个基于 OpenSSL 库的应用层 VPN 实现。和传统 VPN 相比，它的优点是简单易用。OpenVPN能在Solaris、Linux、OpenBSD、FreeBSD、NetBSD、Mac OS X与Windows 2000/XP/Vista上运行，并包含了许多安全性的功能。

OpenVPN服务端

更新系统包

1	root@ubuntu:~# sudo apt update && apt upgrade

查看主机网卡和公网IP

查看主机网卡

root@ubuntu:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:16:3e:0b:8a:30 brd ff:ff:ff:ff:ff:ff
    inet 172.27.15.76/20 brd 172.27.32.255 scope global dynamic eth0
       valid_lft 315288418sec preferred_lft 315288418sec
    inet6 fe80::216:3eff:fe0b:8a30/64 scope link 
       valid_lft forever preferred_lft forever
root@ubuntu:~# ip a show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:16:3e:0b:8a:30 brd ff:ff:ff:ff:ff:ff
    inet 172.27.15.76/20 brd 172.27.32.255 scope global dynamic eth0
       valid_lft 315288410sec preferred_lft 315288410sec
    inet6 fe80::216:3eff:fe0b:8a30/64 scope link 
       valid_lft forever preferred_lft forever

查看公网Ip

1 2	root@ubuntu:~# dig +short myip.opendns.com @resolver1.opendns.com 125.56.79.38

或者

1 2	root@ubuntu:~# dig TXT +short o-o.myaddr.l.google.com @ns1.google.com \| awk -F'"' '{ print $2}' 125.56.79.38

关于IP地址
这里有两个地址，对应两个网卡
- 公网IP：可以直接访问，
- 内网IP：只能在内网访问，

安装脚本

下载安装脚本

1	root@ubuntu:~# wget https://git.io/vpn -O openvpn-install.sh`

注意：
这里可能会下载失败，这个地址会301重定向。如果下载失败，直接把地址换成这个，https://raw.githubusercontent.com/Nyr/openvpn-install/master/openvpn-install.sh。也可以本地下载openvpn-install.sh

脚本安装OpenVPN

root@ubuntu:~# sudo chmod -x openvpn-install
root@ubuntu:~# sudo sh ./openvpn-install.sh
Welcome to this OpenVPN road warrior installer!

Which IPv4 address should be used?
     1) 172.27.15.76
     2) 172.17.0.1
IPv4 address [1]: 1

This server is behind NAT. What is the public IPv4 address or hostname?
Public IPv4 address / hostname [125.56.79.38]: 

Which protocol should OpenVPN use?
   1) UDP (recommended)
   2) TCP
Protocol [1]: 

What port should OpenVPN listen to?
Port [1194]: 

Select a DNS server for the clients:
   1) Current system resolvers
   2) Google
   3) 1.1.1.1
   4) OpenDNS
   5) Quad9
   6) AdGuard
DNS server [1]: 

Enter a name for the first client:
Name [client]: desktop

OpenVPN installation is ready to begin.
Press any key to continue...

安装后续

查看安装结果

稍等片刻就可以执行完，查看安装是否成功

root@ubuntu:~# sudo systemctl status [email protected]
● [email protected] - OpenVPN service for server
     Loaded: loaded (/lib/systemd/system/[email protected]; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2021-12-03 19:48:38 CST; 1s ago
       Docs: man:openvpn(8)
             https://community.openvpn.net/openvpn/wiki/Openvpn24ManPage
             https://community.openvpn.net/openvpn/wiki/HOWTO
   Main PID: 27120 (openvpn)
     Status: "Initialization Sequence Completed"
      Tasks: 1 (limit: 2315)
     Memory: 1.0M
     CGroup: /system.slice/system-openvpn\x2dserver.slice/[email protected]
             └─27120 /usr/sbin/openvpn --status /run/openvpn-server/status-server.log --status-version 2 --suppress-timestamps --config server.conf

Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: Could not determine IPv4/IPv6 protocol. Using AF_INET
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: Socket Buffers: R=[212992->212992] S=[212992->212992]
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: UDPv4 link local (bound): [AF_INET]172.26.5.75:1194
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: UDPv4 link remote: [AF_UNSPEC]
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: GID set to nogroup
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: UID set to nobody
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: MULTI: multi_init called, r=256 v=256
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: IFCONFIG POOL: base=10.8.0.2 size=252, ipv6=0
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: IFCONFIG POOL LIST
Dec 03 19:48:38 iZbp1j7lkpb4u4etrx0dq7Z openvpn[27120]: Initialization Sequence Completed