Show pagesourceOld revisionsBacklinksBack to top × Table of Contents OpenVPN extras Introduction Extras References Web interface Instance management Commercial provider Dynamic connection Dynamic address Network interface Static addresses Site-to-site Disable gateway redirection Split gateway IPv6 gateway TCP Bridging IPv6 Windows client DNS over VPN DNS and domain Kill switch Multi-client Automated OpenVPN extras This article relies on the following: Accessing web interface / command-line interface Managing configs / packages / services / logs Introduction This how-to describes the most common OpenVPN tuning scenarios adapted for OpenWrt. Follow OpenVPN server for server setup and OpenVPN client for client setup. Follow DDNS client to use own server with dynamic IP address. Follow Random generator to overcome low entropy issues. Extras References OpenVPN for BSD/Linux/Windows OpenVPN for Android OpenVPN documentation Web interface If you want to manage VPN instances using web interface. Install the necessary packages and provide instance management. # Install packages opkg update opkg install luci-app-openvpn /etc/init.d/rpcd restart Navigate to LuCI → VPN → OpenVPN to manage OpenVPN instances. Instance management If you need to manage multiple VPN instances or use web interface. Configure VPN instances. # Provide VPN instance management ls /etc/openvpn/*.conf \ | while read -r OVPN_CONF do OVPN_ID="$(basename ${OVPN_CONF%.*} | sed -e "s/\W/_/g")" uci -q delete openvpn.${OVPN_ID} uci set openvpn.${OVPN_ID}="openvpn" uci set openvpn.${OVPN_ID}.enabled="1" uci set openvpn.${OVPN_ID}.config="${OVPN_CONF}" done uci commit openvpn /etc/init.d/openvpn restart Be sure to specify a different VPN interface name for each instance. Commercial provider If you use a commercial VPN provider. Set up credentials for username/password authentication. # Save username/password credentials umask go= cat << EOF > /etc/openvpn/client.auth USERNAME PASSWORD EOF # Configure VPN service cat << EOF >> /etc/openvpn/client.conf auth-user-pass client.auth EOF /etc/init.d/openvpn restart Dynamic connection Set up Hotplug extras to restart VPN client upon reconnecting WAN interface. # Configure hotplug mkdir -p /etc/hotplug.d/online cat << "EOF" > /etc/hotplug.d/online/00-openvpn /etc/init.d/openvpn restart EOF cat << "EOF" >> /etc/sysupgrade.conf /etc/hotplug.d/online/00-openvpn EOF Dynamic address Allow the peer to change its address/port. # Configure VPN service cat << EOF >> /etc/openvpn/client.conf float EOF /etc/init.d/openvpn restart Network interface If you want to set up PBR. Declare the VPN interface. uci del_list firewall.wan.device="tun+" uci add_list firewall.wan.network="vpn" uci commit firewall /etc/init.d/firewall restart uci -q delete network.vpn uci set network.vpn="interface" uci set network.vpn.proto="none" uci set network.vpn.device="tun0" uci commit network /etc/init.d/network restart Be sure to resolve race condition with netifd service. Static addresses Provide static IP address allocation on VPN server assuming that: 192.168.8.0/24 - VPN network fdf1:e8a1:8d3f:8::/64 - IPv6 VPN network umask go=rx mkdir -p /etc/openvpn/ccd cat << EOF > /etc/openvpn/ccd/client ifconfig-push 192.168.8.2 255.255.255.0 ifconfig-ipv6-push fdf1:e8a1:8d3f:8::2/64 EOF cat << EOF >> /etc/openvpn/server.conf client-config-dir ccd EOF /etc/init.d/openvpn restart Site-to-site Implement plain routing between server side LAN and client side LAN assuming that: 192.168.1.0/24 - server side LAN 192.168.2.0/24 - client side LAN Set up static address allocation on VPN server, add route to client side LAN, push route to server side LAN, selectively disable gateway redirection. cat << EOF >> /etc/openvpn/ccd/client iroute 192.168.2.0 255.255.255.0 push-remove redirect-gateway EOF cat << EOF >> /etc/openvpn/server.conf route 192.168.2.0 255.255.255.0 192.168.8.2 push "route 192.168.1.0 255.255.255.0" EOF /etc/init.d/openvpn restart Consider VPN network as private and assign VPN interface to LAN zone on VPN client. uci del_list firewall.wan.device="tun+" uci add_list firewall.lan.device="tun+" uci commit firewall /etc/init.d/firewall restart Disable gateway redirection If you do not need to redirect all traffic to VPN, or want to utilize PBR. Disable gateway redirection on VPN server, or ignore it on VPN client. cat << EOF >> /etc/openvpn/client.conf pull-filter ignore redirect-gateway EOF Split gateway If VPN gateway is separate from your LAN gateway. Implement plain routing between LAN network and VPN network assuming that: 192.168.1.0/24 - LAN network 192.168.1.2/24 - VPN gateway 192.168.8.0/24 - VPN network Add port forwarding for VPN server on LAN gateway. uci -q delete firewall.ovpn uci set firewall.ovpn="redirect" uci set firewall.ovpn.name="Redirect-OpenVPN" uci set firewall.ovpn.src="wan" uci set firewall.ovpn.src_dport="1194" uci set firewall.ovpn.dest="lan" uci set firewall.ovpn.dest_ip="192.168.1.2" uci set firewall.ovpn.family="ipv4" uci set firewall.ovpn.proto="udp" uci set firewall.ovpn.target="DNAT" uci commit firewall /etc/init.d/firewall restart Add route to VPN network via VPN gateway on LAN gateway. uci -q delete network.vpn uci set network.vpn="route" uci set network.vpn.interface="lan" uci set network.vpn.target="192.168.8.0/24" uci set network.vpn.gateway="192.168.1.2" uci commit network /etc/init.d/network restart IPv6 gateway Set up an IPv6 tunnel broker or IPv6 masquerading if necessary. Enable IPv6 tunnel on VPN server, offer IPv6 DNS, redirect IPv6 gateway. OVPN_POOL6="fdf1:e8a1:8d3f:8::/64" OVPN_DNS6="${OVPN_POOL6%/*}1" cat << EOF >> /etc/openvpn/server.conf proto udp6 server-ipv6 ${OVPN_POOL6} push "dhcp-option DNS ${OVPN_DNS6}" push "redirect-gateway ipv6" EOF /etc/init.d/openvpn restart Disable IPv6 source routing on VPN server. Disable ISP prefix delegation to prevent IPv6 leaks on VPN client. TCP Use TCP if necessary. Beware of performance issues. OVPN_PROTO="tcp" cat << EOF >> /etc/openvpn/server.conf proto ${OVPN_PROTO} proto ${OVPN_PROTO}6 EOF /etc/init.d/openvpn restart uci set firewall.ovpn.proto="${OVPN_PROTO}" uci commit firewall /etc/init.d/firewall restart Bridging If you need to utilize bridging. Beware of compatibility issues. OVPN_ADDR="$(uci get network.lan.ipaddr)" OVPN_MASK="$(uci get network.lan.netmask)" OVPN_POOL="${OVPN_ADDR%.*}.128 ${OVPN_ADDR%.*}.254" OVPN_DNS="${OVPN_ADDR}" cat << EOF >> /etc/openvpn/server.conf dev tap server-bridge ${OVPN_ADDR} ${OVPN_MASK} ${OVPN_POOL} push "dhcp-option DNS ${OVPN_DNS}" EOF /etc/init.d/openvpn restart uci -q delete firewall.lan.device uci commit firewall /etc/init.d/firewall restart uci add_list network.@device[0].ports="tap0" uci commit network /etc/init.d/network restart IPv6 Windows client Fix IPv6 routing for Windows desktop client. NETSH_IPV6="C:\\\\Windows\\\\System32\\\\cmd.exe /c netsh interface ipv6" cat << EOF >> /etc/openvpn/client.ovpn script-security 2 up '${NETSH_IPV6} set privacy state=disabled store=active & echo' ipchange '${NETSH_IPV6} set global randomizeidentifiers=disabled store=active & echo' route-up '${NETSH_IPV6} delete route prefix=%ifconfig_ipv6_local%/%ifconfig_ipv6_netbits% interface=%dev_idx% store=active' EOF DNS over VPN Provide DNS for VPN clients in the point-to-point topology on OpenWrt server. Utilize DNS over VPN to prevent DNS leaks on VPN client. Disable peer DNS and configure a VPN-routed DNS provider on OpenWrt client. Modify the VPN connection using NetworkManager on Linux desktop client. nmcli connection modify id VPN_CON \ ipv4.dns-search ~. ipv4.dns-priority -50 \ ipv6.dns-search ~. ipv6.dns-priority -50 Modify the VPN client profile for Windows desktop client. cat << EOF >> /etc/openvpn/client.ovpn block-outside-dns EOF DNS and domain Use DNS and domain provided by VPN server on OpenWrt client. cat << "EOF" > /etc/hotplug.d/net/00-openvpn-resolv if [ "${INTERFACE%%[0-9]*}" = "tun" ] then case "${ACTION}" in (add) RESOLV_CONF="/tmp/resolv.conf.d/resolv.conf.vpn" ;; (remove) RESOLV_CONF="/tmp/resolv.conf.d/resolv.conf.auto" ;; esac uci set dhcp.@dnsmasq[0].resolvfile="${RESOLV_CONF}" /etc/init.d/dnsmasq restart fi EOF cat << "EOF" > /etc/hotplug.d/openvpn/00-resolv env | sed -n -e " /^foreign_option_.*=dhcp-option.*DNS/s//nameserver/p /^foreign_option_.*=dhcp-option.*DOMAIN/s//search/p " | sort -u > /tmp/resolv.conf.d/resolv.conf.vpn EOF cat << "EOF" >> /etc/sysupgrade.conf /etc/hotplug.d/net/00-openvpn-resolv /etc/hotplug.d/openvpn/00-resolv EOF /etc/init.d/openvpn restart Kill switch Prevent traffic leaks on OpenWrt client isolating VPN interface in a separate firewall zone. uci -q delete firewall.vpn uci set firewall.vpn="zone" uci set firewall.vpn.name="vpn" uci set firewall.vpn.input="REJECT" uci set firewall.vpn.output="ACCEPT" uci set firewall.vpn.forward="REJECT" uci set firewall.vpn.masq="1" uci set firewall.vpn.mtu_fix="1" uci add_list firewall.vpn.device="tun+" uci del_list firewall.wan.device="tun+" uci -q delete firewall.@forwarding[0] uci -q delete firewall.lan_vpn uci set firewall.lan_vpn="forwarding" uci set firewall.lan_vpn.src="lan" uci set firewall.lan_vpn.dest="vpn" uci commit firewall /etc/init.d/firewall restart Multi-client Set up multi-client VPN server. Use EasyRSA to add clients or revoke their certificates via CRL. # Add one more client easyrsa build-client-full client1 nopass openvpn --tls-crypt-v2 ${EASYRSA_PKI}/private/server.pem \ --genkey tls-crypt-v2-client ${EASYRSA_PKI}/private/client1.pem # Revoke client certificate easyrsa revoke client # Generate a CRL easyrsa gen-crl # Enable CRL verification OVPN_PKI="/etc/easy-rsa/pki" OVPN_CRL="$(cat ${OVPN_PKI}/crl.pem)" cat << EOF >> /etc/openvpn/server.conf <crl-verify> ${OVPN_CRL} </crl-verify> EOF /etc/init.d/openvpn restart Automated Automated VPN server installation and client profiles generation. URL="https://openwrt.org/_export/code/docs/guide-user/services/vpn/openvpn" cat << EOF > openvpn-server.sh $(uclient-fetch -O - "${URL}/server?codeblock=0") $(uclient-fetch -O - "${URL}/server?codeblock=1") $(uclient-fetch -O - "${URL}/server?codeblock=2") $(uclient-fetch -O - "${URL}/server?codeblock=3") EOF sh openvpn-server.sh This website uses cookies. 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