我已经按照说明配置了我的 OpenVPN 服务器这教程。配置和设置好一切后，我可以毫无问题地将客户端连接到服务器。但是，连接完成后，我无法从客户端访问互联网，也无法通过 ssh 通过其公共 IP 连接到服务器（我可以通过 10.8.0.1 vpn ip 进行 ssh）。此外，我可以 ssh 连接服务器的任何以太网卡（公共和私有 192.168.1...），但无法 ping 或 ssh 连接服务器私有网络上的任何其他计算机。我认为问题在于连接到服务器后，我没有得到命令的答复routes。
连接到 VPN 服务器之前：
$ route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default _gateway 0.0.0.0 UG 20100 0 0 enp2s0
SERVERPUBLICIP _gateway 255.255.255.255 UGH 0 0 0 enp2s0
192.168.8.0 0.0.0.0 255.255.255.0 U 100 0 0 enp2s0
连接到 VPN 服务器后：
$ route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
我的服务器配置文件是：
#################################################
# Sample OpenVPN 2.0 config file for #
# multi-client server. #
# #
# This file is for the server side #
# of a many-clients <-> one-server #
# OpenVPN configuration. #
# #
# OpenVPN also supports #
# single-machine <-> single-machine #
# configurations (See the Examples page #
# on the web site for more info). #
# #
# This config should work on Windows #
# or Linux/BSD systems. Remember on #
# Windows to quote pathnames and use #
# double backslashes, e.g.: #
# "C:\\Program Files\\OpenVPN\\config\\foo.key" #
# #
# Comments are preceded with '#' or ';' #
#################################################
# Which local IP address should OpenVPN
# listen on? (optional)
;local a.b.c.d
# Which TCP/UDP port should OpenVPN listen on?
# If you want to run multiple OpenVPN instances
# on the same machine, use a different port
# number for each one. You will need to
# open up this port on your firewall.
port PORTNUMBER
# TCP or UDP server?
;proto tcp
proto udp
# "dev tun" will create a routed IP tunnel,
# "dev tap" will create an ethernet tunnel.
# Use "dev tap0" if you are ethernet bridging
# and have precreated a tap0 virtual interface
# and bridged it with your ethernet interface.
# If you want to control access policies
# over the VPN, you must create firewall
# rules for the the TUN/TAP interface.
# On non-Windows systems, you can give
# an explicit unit number, such as tun0.
# On Windows, use "dev-node" for this.
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface.
;dev tap
dev tun
# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel if you
# have more than one. On XP SP2 or higher,
# you may need to selectively disable the
# Windows firewall for the TAP adapter.
# Non-Windows systems usually don't need this.
;dev-node MyTap
# SSL/TLS root certificate (ca), certificate
# (cert), and private key (key). Each client
# and the server must have their own cert and
# key file. The server and all clients will
# use the same ca file.
#
# See the "easy-rsa" directory for a series
# of scripts for generating RSA certificates
# and private keys. Remember to use
# a unique Common Name for the server
# and each of the client certificates.
#
# Any X509 key management system can be used.
# OpenVPN can also use a PKCS #12 formatted key file
# (see "pkcs12" directive in man page).
ca ca.crt
cert server.crt
key server.key # This file should be kept secret
# Diffie hellman parameters.
# Generate your own with:
# openssl dhparam -out dh2048.pem 2048
dh dh.pem
# Network topology
# Should be subnet (addressing via IP)
# unless Windows clients v2.0.9 and lower have to
# be supported (then net30, i.e. a /30 per client)
# Defaults to net30 (not recommended)
;topology subnet
# Configure server mode and supply a VPN subnet
# for OpenVPN to draw client addresses from.
# The server will take 10.8.0.1 for itself,
# the rest will be made available to clients.
# Each client will be able to reach the server
# on 10.8.0.1. Comment this line out if you are
# ethernet bridging. See the man page for more info.
server 10.8.0.0 255.255.255.0
# Maintain a record of client <-> virtual IP address
# associations in this file. If OpenVPN goes down or
# is restarted, reconnecting clients can be assigned
# the same virtual IP address from the pool that was
# previously assigned.
ifconfig-pool-persist /var/log/openvpn/ipp.txt
# Configure server mode for ethernet bridging.
# You must first use your OS's bridging capability
# to bridge the TAP interface with the ethernet
# NIC interface. Then you must manually set the
# IP/netmask on the bridge interface, here we
# assume 10.8.0.4/255.255.255.0. Finally we
# must set aside an IP range in this subnet
# (start=10.8.0.50 end=10.8.0.100) to allocate
# to connecting clients. Leave this line commented
# out unless you are ethernet bridging.
;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100
# Configure server mode for ethernet bridging
# using a DHCP-proxy, where clients talk
# to the OpenVPN server-side DHCP server
# to receive their IP address allocation
# and DNS server addresses. You must first use
# your OS's bridging capability to bridge the TAP
# interface with the ethernet NIC interface.
# Note: this mode only works on clients (such as
# Windows), where the client-side TAP adapter is
# bound to a DHCP client.
;server-bridge
# Push routes to the client to allow it
# to reach other private subnets behind
# the server. Remember that these
# private subnets will also need
# to know to route the OpenVPN client
# address pool (10.8.0.0/255.255.255.0)
# back to the OpenVPN server.
;push "route 192.168.10.0 255.255.255.0"
;push "route 192.168.20.0 255.255.255.0"
push "route 192.168.1.0 255.255.255.0"
# To assign specific IP addresses to specific
# clients or if a connecting client has a private
# subnet behind it that should also have VPN access,
# use the subdirectory "ccd" for client-specific
# configuration files (see man page for more info).
# EXAMPLE: Suppose the client
# having the certificate common name "Thelonious"
# also has a small subnet behind his connecting
# machine, such as 192.168.40.128/255.255.255.248.
# First, uncomment out these lines:
;client-config-dir ccd
;route 192.168.40.128 255.255.255.248
# Then create a file ccd/Thelonious with this line:
# iroute 192.168.40.128 255.255.255.248
# This will allow Thelonious' private subnet to
# access the VPN. This example will only work
# if you are routing, not bridging, i.e. you are
# using "dev tun" and "server" directives.
# EXAMPLE: Suppose you want to give
# Thelonious a fixed VPN IP address of 10.9.0.1.
# First uncomment out these lines:
;client-config-dir ccd
;route 10.9.0.0 255.255.255.252
# Then add this line to ccd/Thelonious:
# ifconfig-push 10.9.0.1 10.9.0.2
# Suppose that you want to enable different
# firewall access policies for different groups
# of clients. There are two methods:
# (1) Run multiple OpenVPN daemons, one for each
# group, and firewall the TUN/TAP interface
# for each group/daemon appropriately.
# (2) (Advanced) Create a script to dynamically
# modify the firewall in response to access
# from different clients. See man
# page for more info on learn-address script.
;learn-address ./script
# If enabled, this directive will configure
# all clients to redirect their default
# network gateway through the VPN, causing
# all IP traffic such as web browsing and
# and DNS lookups to go through the VPN
# (The OpenVPN server machine may need to NAT
# or bridge the TUN/TAP interface to the internet
# in order for this to work properly).
;push "redirect-gateway def1 bypass-dhcp"
push "redirect-gateway local def1"
# Certain Windows-specific network settings
# can be pushed to clients, such as DNS
# or WINS server addresses. CAVEAT:
# http://openvpn.net/faq.html#dhcpcaveats
# The addresses below refer to the public
# DNS servers provided by opendns.com.
;push "dhcp-option DNS 10.8.0.1"
push "dhcp-option DNS 192.168.1.1"
;push "dhcp-option DNS SERVERPUBLICIP"
# Uncomment this directive to allow different
# clients to be able to "see" each other.
# By default, clients will only see the server.
# To force clients to only see the server, you
# will also need to appropriately firewall the
# server's TUN/TAP interface.
;client-to-client
# Uncomment this directive if multiple clients
# might connect with the same certificate/key
# files or common names. This is recommended
# only for testing purposes. For production use,
# each client should have its own certificate/key
# pair.
#
# IF YOU HAVE NOT GENERATED INDIVIDUAL
# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,
# EACH HAVING ITS OWN UNIQUE "COMMON NAME",
# UNCOMMENT THIS LINE OUT.
;duplicate-cn
# The keepalive directive causes ping-like
# messages to be sent back and forth over
# the link so that each side knows when
# the other side has gone down.
# Ping every 10 seconds, assume that remote
# peer is down if no ping received during
# a 120 second time period.
keepalive 10 120
# For extra security beyond that provided
# by SSL/TLS, create an HMAC firewall"
# to help block DoS attacks and UDP port flooding.
#
# Generate with:
# openvpn --genkey --secret ta.key
#
# The server and each client must have
# a copy of this key.
# The second parameter should be '0'
# on the server and '1' on the clients.
tls-auth ta.key 0 # This file is secret
# Select a cryptographic cipher.
# This config item must be copied to
# the client config file as well.
# Note that v2.4 client/server will automatically
# negotiate AES-256-GCM in TLS mode.
# See also the ncp-cipher option in the manpage
cipher AES-256-CBC
auth SHA256
# Enable compression on the VPN link and push the
# option to the client (v2.4+ only, for earlier
# versions see below)
;compress lz4-v2
;push "compress lz4-v2"
# For compression compatible with older clients use comp-lzo
# If you enable it here, you must also
# enable it in the client config file.
;comp-lzo
# The maximum number of concurrently connected
# clients we want to allow.
;max-clients 100
# It's a good idea to reduce the OpenVPN
# daemon's privileges after initialization.
#
# You can uncomment this out on
# non-Windows systems.
user nobody
group nogroup
# The persist options will try to avoid
# accessing certain resources on restart
# that may no longer be accessible because
# of the privilege downgrade.
persist-key
persist-tun
# Output a short status file showing
# current connections, truncated
# and rewritten every minute.
status /var/log/openvpn/openvpn-status.log
# By default, log messages will go to the syslog (or
# on Windows, if running as a service, they will go to
# the "\Program Files\OpenVPN\log" directory).
# Use log or log-append to override this default.
# "log" will truncate the log file on OpenVPN startup,
# while "log-append" will append to it. Use one
# or the other (but not both).
;log /var/log/openvpn/openvpn.log
;log-append /var/log/openvpn/openvpn.log
# Set the appropriate level of log
# file verbosity.
#
# 0 is silent, except for fatal errors
# 4 is reasonable for general usage
# 5 and 6 can help to debug connection problems
# 9 is extremely verbose
verb 3
# Silence repeating messages. At most 20
# sequential messages of the same message
# category will be output to the log.
;mute 20
# Notify the client that when the server restarts so it
# can automatically reconnect.
explicit-exit-notify 1
在此文件中，PORTNUMBER并且SERVERPUBLICIP已设置为我的公共IP和路由器防火墙上打开的端口。
我的 OpenVPN 日志（/var/log/openvpn/openvpn-status.log）显示（客户端连接后）：
OpenVPN CLIENT LIST
Updated,Wed Oct 16 08:25:13 2019
Common Name,Real Address,Bytes Received,Bytes Sent,Connected Since
apalomer,SOMEOTHERPUBLICIP:54864,13164,3569,Wed Oct 16 08:25:03 2019
ROUTING TABLE
Virtual Address,Common Name,Real Address,Last Ref
10.8.0.6,apalomer,SOMEOTHERPUBLICIP:54864,Wed Oct 16 08:25:12 2019
GLOBAL STATS
Max bcast/mcast queue length,1
END
其中 SOMEOTHERPUBLICIP 不是服务器的公共 IP。
服务器网络配置为：
enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.108 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::e28f:a01d:c043:dc41 prefixlen 64 scopeid 0x20<link>
ether e0:3f:49:47:95:8f txqueuelen 1000 (Ethernet)
RX packets 61664 bytes 4785172 (4.7 MB)
RX errors 0 dropped 8818 overruns 0 frame 0
TX packets 18200 bytes 1656024 (1.6 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp7s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet SERVERPUBLICIP netmask 255.255.255.0 broadcast SERVERPUBLICIP.255
inet6 fe80::9219:cc1d:57f5:ecc7 prefixlen 64 scopeid 0x20<link>
ether e8:94:f6:02:85:4d txqueuelen 1000 (Ethernet)
RX packets 656236 bytes 511487988 (511.4 MB)
RX errors 0 dropped 164 overruns 0 frame 0
TX packets 187366 bytes 16304575 (16.3 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 126461 bytes 14656046 (14.6 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 126461 bytes 14656046 (14.6 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.8.0.1 netmask 255.255.255.255 destination 10.8.0.2
inet6 fe80::d903:b10c:65b0:23fc prefixlen 64 scopeid 0x20<link>
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 100 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 8 bytes 384 (384.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp4s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 10:fe:ed:8c:25:3d txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
连接服务器后客户端的网络配置为：
enp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.8.4 netmask 255.255.255.0 broadcast 192.168.8.255
inet6 fe80::e84e:bf84:9cf:7220 prefixlen 64 scopeid 0x20<link>
ether 00:d8:61:31:40:72 txqueuelen 1000 (Ethernet)
RX packets 431128 bytes 304709063 (304.7 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 326425 bytes 74418551 (74.4 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 50:3e:aa:0d:a1:3d txqueuelen 1000 (Ethernet)
RX packets 26793 bytes 4025965 (4.0 MB)
RX errors 0 dropped 514 overruns 0 frame 0
TX packets 6865 bytes 695724 (695.7 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 18262 bytes 1556456 (1.5 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18262 bytes 1556456 (1.5 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.8.0.6 netmask 255.255.255.255 destination 10.8.0.5
inet6 fe80::6c94:cddd:8cf5:e769 prefixlen 64 scopeid 0x20<link>
unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 txqueuelen 100 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 437 bytes 58238 (58.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp4s0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether f4:d1:08:d9:8e:65 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
使用此配置，我可以 ping 通10.8.0.1（服务器 VPN IP），但无法 ping 通 192.168.1.108（服务器专用网络 IP）或服务器公共 IP。如果按照 kukulo 在评论中建议的更改进行操作，我观察到了相同的行为（将推送“dhcp-option DNS 10.8.0.1”中的 ip 地址替换为您的 dhcp 服务器的本地 dhcp ip 地址和将推送“redirect-gateway def1bypass-dhcp”替换为推送“redirect-gatewaylocaldef1”）
在服务器中，IPv4 转发已打开（从这教程部分）：
cat /proc/sys/net/ipv4/ip_forward
1
服务器默认路由是：
$ ip route | grep default
default via 84.88.154.1 dev enp7s0 proto static metric 100
default via 192.168.1.1 dev enp3s0 proto static metric 20101
客户端默认路由是：
$ ip route | grep default
default via 192.168.8.254 dev enp2s0 proto dhcp metric 20106
服务器/etc/default/ufw是：
# /etc/default/ufw
#
# Set to yes to apply rules to support IPv6 (no means only IPv6 on loopback
# accepted). You will need to 'disable' and then 'enable' the firewall for
# the changes to take affect.
IPV6=yes
# Set the default input policy to ACCEPT, DROP, or REJECT. Please note that if
# you change this you will most likely want to adjust your rules.
DEFAULT_INPUT_POLICY="DROP"
# Set the default output policy to ACCEPT, DROP, or REJECT. Please note that if
# you change this you will most likely want to adjust your rules.
DEFAULT_OUTPUT_POLICY="ACCEPT"
# Set the default forward policy to ACCEPT, DROP or REJECT. Please note that
# if you change this you will most likely want to adjust your rules
DEFAULT_FORWARD_POLICY="ACCEPT"
# Set the default application policy to ACCEPT, DROP, REJECT or SKIP. Please
# note that setting this to ACCEPT may be a security risk. See 'man ufw' for
# details
DEFAULT_APPLICATION_POLICY="SKIP"
# By default, ufw only touches its own chains. Set this to 'yes' to have ufw
# manage the built-in chains too. Warning: setting this to 'yes' will break
# non-ufw managed firewall rules
MANAGE_BUILTINS=no
#
# IPT backend
#
# only enable if using iptables backend
IPT_SYSCTL=/etc/ufw/sysctl.conf
# Extra connection tracking modules to load. Complete list can be found in
# net/netfilter/Kconfig of your kernel source. Some common modules:
# nf_conntrack_irc, nf_nat_irc: DCC (Direct Client to Client) support
# nf_conntrack_netbios_ns: NetBIOS (samba) client support
# nf_conntrack_pptp, nf_nat_pptp: PPTP over stateful firewall/NAT
# nf_conntrack_ftp, nf_nat_ftp: active FTP support
# nf_conntrack_tftp, nf_nat_tftp: TFTP support (server side)
# nf_conntrack_sane: sane support
IPT_MODULES="nf_conntrack_ftp nf_nat_ftp nf_conntrack_netbios_ns"
服务器的内容/etc/ufw/before.rules是：
#
# rules.before
#
# Rules that should be run before the ufw command line added rules. Custom
# rules should be added to one of these chains:
# ufw-before-input
# ufw-before-output
# ufw-before-forward
#
# START OPENVPN RULES
# NAT table rules
*nat
#:POSTROUTING ACCEPT [0:0]
# Allow traffic from OpenVPN client to wlp11s0 (change to the interface you discovered!)
-A POSTROUTING -s 10.8.0.0/8 -o enp3s0 -j MASQUERADE
COMMIT
# END OPENVPN RULES
# Don't delete these required lines, otherwise there will be errors
*filter
:ufw-before-input - [0:0]
:ufw-before-output - [0:0]
:ufw-before-forward - [0:0]
:ufw-not-local - [0:0]
# End required lines
# allow all on loopback
-A ufw-before-input -i lo -j ACCEPT
-A ufw-before-output -o lo -j ACCEPT
# quickly process packets for which we already have a connection
-A ufw-before-input -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-output -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-forward -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
# drop INVALID packets (logs these in loglevel medium and higher)
-A ufw-before-input -m conntrack --ctstate INVALID -j ufw-logging-deny
-A ufw-before-input -m conntrack --ctstate INVALID -j DROP
# ok icmp codes for INPUT
-A ufw-before-input -p icmp --icmp-type destination-unreachable -j ACCEPT
-A ufw-before-input -p icmp --icmp-type time-exceeded -j ACCEPT
-A ufw-before-input -p icmp --icmp-type parameter-problem -j ACCEPT
-A ufw-before-input -p icmp --icmp-type echo-request -j ACCEPT
# ok icmp code for FORWARD
-A ufw-before-forward -p icmp --icmp-type destination-unreachable -j ACCEPT
-A ufw-before-forward -p icmp --icmp-type time-exceeded -j ACCEPT
-A ufw-before-forward -p icmp --icmp-type parameter-problem -j ACCEPT
-A ufw-before-forward -p icmp --icmp-type echo-request -j ACCEPT
# allow dhcp client to work
-A ufw-before-input -p udp --sport 67 --dport 68 -j ACCEPT
#
# ufw-not-local
#
-A ufw-before-input -j ufw-not-local
# if LOCAL, RETURN
-A ufw-not-local -m addrtype --dst-type LOCAL -j RETURN
# if MULTICAST, RETURN
-A ufw-not-local -m addrtype --dst-type MULTICAST -j RETURN
# if BROADCAST, RETURN
-A ufw-not-local -m addrtype --dst-type BROADCAST -j RETURN
# all other non-local packets are dropped
-A ufw-not-local -m limit --limit 3/min --limit-burst 10 -j ufw-logging-deny
-A ufw-not-local -j DROP
# allow MULTICAST mDNS for service discovery (be sure the MULTICAST line above
# is uncommented)
-A ufw-before-input -p udp -d 224.0.0.251 --dport 5353 -j ACCEPT
# allow MULTICAST UPnP for service discovery (be sure the MULTICAST line above
# is uncommented)
-A ufw-before-input -p udp -d 239.255.255.250 --dport 1900 -j ACCEPT
# don't delete the 'COMMIT' line or these rules won't be processed
COMMIT
关于我能做什么有什么想法吗？
我试过了：
答案1
检查您的默认路线：
ip route | grep default输出
default via 84.88.154.1 dev enp7s0 proto static metric 100 default via 192.168.1.1 dev enp3s0 proto static metric 20101当 enp3s0 是你的内部网络默认输出接口时，
命令：
sudo nano /etc/ufw/before.rules编辑 before.rules 文件：
/etc/ufw/before.rules：
#
# rules.before
#
# Rules that should be run before the ufw command line added rules. Custom
# rules should be added to one of these chains:
# ufw-before-input
# ufw-before-output
# ufw-before-forward
#
# START OPENVPN RULES
# NAT table rules
*nat
:POSTROUTING ACCEPT [0:0]
# Allow traffic from OpenVPN client to enp3s0 (change to the interface you discovered!)
-A POSTROUTING -s 10.8.0.0/8 -o enp3s0 -j MASQUERADE
COMMIT
# END OPENVPN RULES
# Don't delete these required lines, otherwise there will be errors
*filter
. . .
命令：
sudo nano /etc/default/ufw更改：/etc/default/ufw：
DEFAULT_FORWARD_POLICY="ACCEPT"命令：
sudo ufw disable sudo ufw enable
答案2
实际正确的答案是您有redirect-gateway指定的选项。
请参阅此处的第一个答案： https://serverfault.com/questions/480069/how-to-force-all-traffic-through-vpn
答案3
我找到了答案。问题出在 iptables 的 NAT 上：
sudo iptables -t nat -L --line-numbers
Chain PREROUTING (policy ACCEPT)
num target prot opt source destination
Chain INPUT (policy ACCEPT)
num target prot opt source destination
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
Chain POSTROUTING (policy ACCEPT)
num target prot opt source destination
1 MASQUERADE all -- 10.8.0.0/24 anywhere
2 SNAT all -- 10.8.0.0/24 !10.8.0.0/24 to:84.88.154.XXX
需要删除 POSTROUTING 2 号：
sudo iptables -t nat -D POSTROUTING 2
但是，这只能解决问题，直到系统重新启动为止。重新启动后，此行又会出现在 iptables 中，需要再次将其删除。
答案4
可能是 OpenVPN Linux 客户端安装时的权限问题？因为它没有创建隧道。 所以我自己做了一个（这是实际问题）：
ip tuntap add name tun0 mode tun
ip link show
如果您的版本ip不支持按如下方式
tuntap使用：tunctlhttps://serverfault.com/a/347900
来源：https://www.naturalborncoder.com/virtualization/2014/10/17/understanding-tun-tap-interfaces
替代解决方案是尝试官方 openvpn3-linux 客户端和安装程序，它应该为您完成配置：https://github.com/OpenVPN/openvpn3-linux