我安装了 strongswan ikev2 vpn在 ubunut 上多次没有问题。但现在在新安装的 ubuntu 服务器上我无法运行它。连接到 vpn 确实有效，但我无法获得互联网连接。连接到 vpn 时我仍然可以连接到服务器，所以我猜 ufw 防火墙不会将我的连接路由到互联网。
我尝试使用“ufw default allow”来允许 ufw 防火墙上的所有内容。
在 ufw.log 中，它仍然显示从互联网到我的 ip（服务器）的连接仍然被阻止，我不知道这是否是导致它不起作用的原因。
这是我的 ufw 配置：
/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
#
*nat
-A POSTROUTING -s 10.10.10.0/24 -o enp2s0 -m policy --pol ipsec --dir out -j ACCEPT
-A POSTROUTING -s 10.10.10.0/24 -o enp2s0 -j MASQUERADE
COMMIT
*mangle
-A FORWARD --match policy --pol ipsec --dir in -s 10.10.10.0/24 -o enp2s0 -p tcp -m tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1361:1536 -j TCPMSS --set-mss 1360
COMMIT
# 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
-A ufw-before-forward --match policy --pol ipsec --dir in --proto esp -s 10.10.10.0/24 -j ACCEPT
-A ufw-before-forward --match policy --pol ipsec --dir out --proto esp -d 10.10.10.0/24 -j ACCEPT
# 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
/etc/ufw/sysctl.conf：
#
# Configuration file for setting network variables. Please note these settings
# override /etc/sysctl.conf and /etc/sysctl.d. If you prefer to use
# /etc/sysctl.conf, please adjust IPT_SYSCTL in /etc/default/ufw. See
# Documentation/networking/ip-sysctl.txt in the kernel source code for more
# information.
#
# Uncomment this to allow this host to route packets between interfaces
#net/ipv4/ip_forward=1
#net/ipv6/conf/default/forwarding=1
#net/ipv6/conf/all/forwarding=1
# Disable ICMP redirects. ICMP redirects are rarely used but can be used in
# MITM (man-in-the-middle) attacks. Disabling ICMP may disrupt legitimate
# traffic to those sites.
net/ipv4/conf/default/accept_redirects=0
net/ipv6/conf/all/accept_redirects=0
net/ipv6/conf/default/accept_redirects=0
# Ignore bogus ICMP errors
net/ipv4/icmp_echo_ignore_broadcasts=1
net/ipv4/icmp_ignore_bogus_error_responses=1
net/ipv4/icmp_echo_ignore_all=0
# Don't log Martian Packets (impossible addresses)
# packets
net/ipv4/conf/all/log_martians=0
net/ipv4/conf/default/log_martians=0
#net/ipv4/tcp_fin_timeout=30
#net/ipv4/tcp_keepalive_intvl=1800
# Uncomment this to turn off ipv6 autoconfiguration
#net/ipv6/conf/default/autoconf=1
#net/ipv6/conf/all/autoconf=1
# Uncomment this to enable ipv6 privacy addressing
#net/ipv6/conf/default/use_tempaddr=2
#net/ipv6/conf/all/use_tempaddr=2
net/ipv4/ip_forward=1
net/ipv4/conf/all/accept_redirects=0
net/ipv4/conf/all/send_redirects=0
net/ipv4/ip_no_pmtu_disc=1
ufw 状态：
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
22/tcp ALLOW Anywhere
20 ALLOW Anywhere
25565 ALLOW Anywhere
500,4500/udp ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
22/tcp (v6) ALLOW Anywhere (v6)
20 (v6) ALLOW Anywhere (v6)
25565 (v6) ALLOW Anywhere (v6)
500,4500/udp (v6) ALLOW Anywhere (v6)