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#!/bin/sh |
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# |
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# Script for automatic configuration of IPsec/L2TP VPN server on CentOS/RHEL 6 & 7. |
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# Works on dedicated servers or any KVM- or XEN-based Virtual Private Server (VPS). |
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# It can also be used as the Amazon EC2 "user-data" with the official CentOS 7 AMI. |
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# Note that the official CentOS 6 AMI does NOT come with cloud-init, so you need to |
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# run this script manually after instance creation. |
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# |
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# DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC! THIS IS MEANT TO BE RUN |
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# ON YOUR DEDICATED SERVER OR VPS! |
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# |
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# Copyright (C) 2015 Lin Song |
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# Based on the work of Thomas Sarlandie (Copyright 2012) |
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# |
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# This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 |
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# Unported License: http://creativecommons.org/licenses/by-sa/3.0/ |
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# |
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# Attribution required: please include my name in any derivative and let me |
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# know how you have improved it! |
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if [ "$(uname)" = "Darwin" ]; then |
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echo 'DO NOT run this script on your Mac! It should only be run on a Dedicated Server / VPS' |
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echo 'or a newly-created EC2 instance, after you have modified it to set the variables below.' |
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exit |
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fi |
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if [ ! -f /etc/redhat-release ]; then |
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echo "Looks like you aren't running this script on a CentOS/RHEL system." |
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exit |
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fi |
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if [ "$(uname -m)" != "x86_64" ]; then |
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echo "Sorry, this script only supports 64-bit CentOS/RHEL." |
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exit |
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fi |
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if [ "$(id -u)" != 0 ]; then |
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echo "Sorry, you need to run this script as root." |
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exit |
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fi |
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# Please define your own values for those variables |
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IPSEC_PSK=your_very_secure_key |
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VPN_USER=your_username |
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VPN_PASSWORD=your_very_secure_password |
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# If you need multiple VPN users with different credentials, |
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# please see: https://gist.github.com/hwdsl2/123b886f29f4c689f531 |
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# Important Notes: |
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# For Windows users, a registry change is required to allow connections |
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# to a VPN server behind NAT. Refer to section "Error 809" on this page: |
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# https://documentation.meraki.com/MX-Z/Client_VPN/Troubleshooting_Client_VPN |
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# iPhone/iOS users may need to replace this line in ipsec.conf: |
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# "rightprotoport=17/%any" with "rightprotoport=17/0". |
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# If using Amazon EC2, these ports must be open in the security group of |
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# your VPN server: UDP ports 500 & 4500, and TCP port 22 (optional, for SSH). |
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# Install wget, dig (bind-utils) and nano |
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yum -y install wget bind-utils nano |
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echo 'If the script hangs here, press Ctrl-C to interrupt, then edit it and comment out' |
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echo 'the next two lines PUBLIC_IP= and PRIVATE_IP=, OR replace them with the actual IPs.' |
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# In Amazon EC2, these two variables will be found automatically. |
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# For all other servers, you may replace them with the actual IPs, |
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# or comment out and let the script auto-detect in the next section. |
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# If your server only has a public IP, use that IP on both lines. |
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PUBLIC_IP=$(wget --retry-connrefused -t 3 -T 15 -qO- 'http://169.254.169.254/latest/meta-data/public-ipv4') |
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PRIVATE_IP=$(wget --retry-connrefused -t 3 -T 15 -qO- 'http://169.254.169.254/latest/meta-data/local-ipv4') |
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# Attempt to find server IPs automatically for non-EC2 servers |
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[ "$PUBLIC_IP" = "" ] && PUBLIC_IP=$(dig +short myip.opendns.com @resolver1.opendns.com) |
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[ "$PUBLIC_IP" = "" ] && PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipecho.net/plain) |
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[ "$PUBLIC_IP" = "" ] && { echo "Could not find Public IP, please edit the VPN script manually."; exit; } |
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[ "$PRIVATE_IP" = "" ] && PRIVATE_IP=$(ifconfig eth0 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*') |
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[ "$PRIVATE_IP" = "" ] && { echo "Could not find Private IP, please edit the VPN script manually."; exit; } |
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# Create and change to working dir |
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mkdir -p /opt/src |
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cd /opt/src |
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# Add the EPEL repository |
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if grep -qs "release 6" /etc/redhat-release; then |
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EPEL_RPM="epel-release-6-8.noarch.rpm" |
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EPEL_URL="http://download.fedoraproject.org/pub/epel/6/x86_64/$EPEL_RPM" |
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elif grep -qs "release 7" /etc/redhat-release; then |
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EPEL_RPM="epel-release-7-5.noarch.rpm" |
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EPEL_URL="http://download.fedoraproject.org/pub/epel/7/x86_64/e/$EPEL_RPM" |
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else |
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echo "Sorry, this script only supports versions 6 and 7 of CentOS/RHEL." |
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exit |
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fi |
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wget -t 3 -T 30 -nv -O $EPEL_RPM $EPEL_URL |
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[ ! -f $EPEL_RPM ] && { echo "Could not retrieve the EPEL repository RPM file. Aborting."; exit; } |
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rpm -ivh --force $EPEL_RPM && rm -f $EPEL_RPM |
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# Install necessary packages |
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yum -y install nss-devel nspr-devel pkgconfig pam-devel \ |
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libcap-ng-devel libselinux-devel \ |
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curl-devel gmp-devel flex bison gcc make \ |
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fipscheck-devel unbound-devel gmp gmp-devel xmlto |
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yum -y install ppp xl2tpd |
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# Installed Libevent 2. Use backported version for CentOS 6. |
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if grep -qs "release 6" /etc/redhat-release; then |
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LE2_URL="https://people.redhat.com/pwouters/libreswan-rhel6" |
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RPM1="libevent2-2.0.21-1.el6.x86_64.rpm" |
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RPM2="libevent2-devel-2.0.21-1.el6.x86_64.rpm" |
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wget -t 3 -T 30 -nv -O $RPM1 $LE2_URL/$RPM1 |
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wget -t 3 -T 30 -nv -O $RPM2 $LE2_URL/$RPM2 |
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[ ! -f $RPM1 ] || [ ! -f $RPM2 ] && { echo "Could not retrieve the Libevent2 RPM file(s). Aborting."; exit; } |
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rpm -ivh --force $RPM1 $RPM2 && rm -f $RPM1 $RPM2 |
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elif grep -qs "release 7" /etc/redhat-release; then |
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yum -y install libevent-devel |
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fi |
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# Compile and install Libreswan (https://libreswan.org/) |
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# To upgrade Libreswan when a newer version is available, just re-run these |
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# commands with the new "SWAN_VER", then restore SELinux contexts using |
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# the commands at the end of this script, and finally restart services with |
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# "service ipsec restart" and "service xl2tpd restart". |
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SWAN_VER=3.15 |
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SWAN_URL=https://download.libreswan.org/libreswan-${SWAN_VER}.tar.gz |
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wget -t 3 -T 30 -qO- $SWAN_URL | tar xvz |
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[ ! -d libreswan-${SWAN_VER} ] && { echo "Could not retrieve the Libreswan source file. Aborting."; exit; } |
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cd libreswan-${SWAN_VER} |
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# Workaround for Libreswan 3.15 compile issues |
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cat > Makefile.inc.local <<EOF |
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WERROR_CFLAGS = |
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EOF |
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make programs && make install |
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# Prepare various config files |
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cat > /etc/ipsec.conf <<EOF |
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version 2.0 |
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config setup |
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dumpdir=/var/run/pluto/ |
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nat_traversal=yes |
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virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12,%v4:!192.168.42.0/24 |
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oe=off |
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protostack=netkey |
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nhelpers=0 |
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interfaces=%defaultroute |
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conn vpnpsk |
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connaddrfamily=ipv4 |
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auto=add |
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left=$PRIVATE_IP |
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leftid=$PUBLIC_IP |
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leftsubnet=$PRIVATE_IP/32 |
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leftnexthop=%defaultroute |
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leftprotoport=17/1701 |
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rightprotoport=17/%any |
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right=%any |
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rightsubnetwithin=0.0.0.0/0 |
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forceencaps=yes |
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authby=secret |
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pfs=no |
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type=transport |
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auth=esp |
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ike=3des-sha1,aes-sha1 |
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phase2alg=3des-sha1,aes-sha1 |
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rekey=no |
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keyingtries=5 |
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dpddelay=30 |
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dpdtimeout=120 |
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dpdaction=clear |
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EOF |
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cat > /etc/ipsec.secrets <<EOF |
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$PUBLIC_IP %any : PSK "$IPSEC_PSK" |
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EOF |
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cat > /etc/xl2tpd/xl2tpd.conf <<EOF |
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[global] |
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port = 1701 |
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;debug avp = yes |
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;debug network = yes |
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;debug state = yes |
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;debug tunnel = yes |
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[lns default] |
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ip range = 192.168.42.10-192.168.42.250 |
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local ip = 192.168.42.1 |
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require chap = yes |
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refuse pap = yes |
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require authentication = yes |
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name = l2tpd |
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;ppp debug = yes |
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pppoptfile = /etc/ppp/options.xl2tpd |
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length bit = yes |
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EOF |
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cat > /etc/ppp/options.xl2tpd <<EOF |
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ipcp-accept-local |
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ipcp-accept-remote |
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ms-dns 8.8.8.8 |
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ms-dns 8.8.4.4 |
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noccp |
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auth |
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crtscts |
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idle 1800 |
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mtu 1280 |
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mru 1280 |
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lock |
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lcp-echo-failure 10 |
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lcp-echo-interval 60 |
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connect-delay 5000 |
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EOF |
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cat > /etc/ppp/chap-secrets <<EOF |
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# Secrets for authentication using CHAP |
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# client server secret IP addresses |
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$VPN_USER l2tpd $VPN_PASSWORD * |
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EOF |
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/bin/cp -f /etc/sysctl.conf /etc/sysctl.conf.old-$(date +%Y-%m-%d-%H:%M:%S) 2>/dev/null |
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cat > /etc/sysctl.conf <<EOF |
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kernel.sysrq = 0 |
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kernel.core_uses_pid = 1 |
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net.ipv4.tcp_syncookies = 1 |
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kernel.msgmnb = 65536 |
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kernel.msgmax = 65536 |
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kernel.shmmax = 68719476736 |
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kernel.shmall = 4294967296 |
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net.ipv4.ip_forward = 1 |
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net.ipv4.conf.all.accept_source_route = 0 |
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net.ipv4.conf.default.accept_source_route = 0 |
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net.ipv4.conf.all.log_martians = 1 |
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net.ipv4.conf.default.log_martians = 1 |
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net.ipv4.conf.all.accept_redirects = 0 |
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net.ipv4.conf.default.accept_redirects = 0 |
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net.ipv4.conf.all.send_redirects = 0 |
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net.ipv4.conf.default.send_redirects = 0 |
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net.ipv4.conf.all.rp_filter = 0 |
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net.ipv4.conf.default.rp_filter = 0 |
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net.ipv6.conf.all.disable_ipv6=1 |
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net.ipv6.conf.default.disable_ipv6=1 |
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net.ipv4.icmp_echo_ignore_broadcasts = 1 |
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net.ipv4.icmp_ignore_bogus_error_responses = 1 |
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net.ipv4.conf.all.secure_redirects = 0 |
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net.ipv4.conf.default.secure_redirects = 0 |
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kernel.randomize_va_space = 1 |
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net.core.wmem_max=12582912 |
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net.core.rmem_max=12582912 |
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net.ipv4.tcp_rmem= 10240 87380 12582912 |
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net.ipv4.tcp_wmem= 10240 87380 12582912 |
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EOF |
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/bin/cp -f /etc/sysconfig/iptables /etc/sysconfig/iptables.old-$(date +%Y-%m-%d-%H:%M:%S) 2>/dev/null |
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cat > /etc/sysconfig/iptables <<EOF |
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*filter |
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:INPUT ACCEPT [0:0] |
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:FORWARD ACCEPT [0:0] |
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:OUTPUT ACCEPT [0:0] |
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:ICMPALL - [0:0] |
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-A INPUT -m conntrack --ctstate INVALID -j DROP |
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-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT |
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-A INPUT -i lo -j ACCEPT |
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-A INPUT -p icmp --icmp-type 255 -j ICMPALL |
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-A INPUT -p udp --dport 67:68 --sport 67:68 -j ACCEPT |
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-A INPUT -p tcp --dport 22 -j ACCEPT |
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-A INPUT -p udp -m multiport --dports 500,4500 -j ACCEPT |
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-A INPUT -p udp --dport 1701 -m policy --dir in --pol ipsec -j ACCEPT |
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-A INPUT -p udp --dport 1701 -j DROP |
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-A INPUT -j DROP |
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-A FORWARD -m conntrack --ctstate INVALID -j DROP |
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-A FORWARD -i eth+ -o ppp+ -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT |
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-A FORWARD -i ppp+ -o eth+ -j ACCEPT |
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# If you wish to allow traffic between VPN clients themselves, uncomment this line: |
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# -A FORWARD -i ppp+ -o ppp+ -s 192.168.42.0/24 -d 192.168.42.0/24 -j ACCEPT |
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-A FORWARD -j DROP |
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-A ICMPALL -p icmp -f -j DROP |
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-A ICMPALL -p icmp --icmp-type 0 -j ACCEPT |
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-A ICMPALL -p icmp --icmp-type 3 -j ACCEPT |
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-A ICMPALL -p icmp --icmp-type 4 -j ACCEPT |
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-A ICMPALL -p icmp --icmp-type 8 -j ACCEPT |
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-A ICMPALL -p icmp --icmp-type 11 -j ACCEPT |
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-A ICMPALL -p icmp -j DROP |
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COMMIT |
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*nat |
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:PREROUTING ACCEPT [0:0] |
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:OUTPUT ACCEPT [0:0] |
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:POSTROUTING ACCEPT [0:0] |
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-A POSTROUTING -s 192.168.42.0/24 -o eth+ -j SNAT --to-source ${PRIVATE_IP} |
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COMMIT |
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EOF |
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/bin/cp -f /etc/rc.local /etc/rc.local.old-$(date +%Y-%m-%d-%H:%M:%S) 2>/dev/null |
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cat > /etc/rc.local <<EOF |
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#!/bin/sh |
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# |
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# This script will be executed *after* all the other init scripts. |
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# You can put your own initialization stuff in here if you don't |
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# want to do the full Sys V style init stuff. |
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touch /var/lock/subsys/local |
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/sbin/iptables-restore < /etc/sysconfig/iptables |
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/sbin/service ipsec restart |
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/sbin/service xl2tpd restart |
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echo 1 > /proc/sys/net/ipv4/ip_forward |
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EOF |
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if [ ! -f /etc/ipsec.d/cert8.db ] ; then |
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echo > /var/tmp/libreswan-nss-pwd |
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/usr/bin/certutil -N -f /var/tmp/libreswan-nss-pwd -d /etc/ipsec.d |
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/bin/rm -f /var/tmp/libreswan-nss-pwd |
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fi |
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# Restore SELinux contexts |
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restorecon /etc/ipsec.d/*db 2>/dev/null |
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restorecon /usr/local/sbin -Rv 2>/dev/null |
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restorecon /usr/local/libexec/ipsec -Rv 2>/dev/null |
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/sbin/sysctl -p |
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/bin/chmod 600 /etc/ipsec.secrets /etc/ppp/chap-secrets |
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/sbin/iptables-restore < /etc/sysconfig/iptables |
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/sbin/service ipsec restart |
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/sbin/service xl2tpd restart |
