L2TP + IPsec VPN server on Raspberry Pi (IOS 10 support)
First at all, what is Raspbery Pi?
It is super small computer (credit card size) running on version of Debian linux called Raspbian. It is ideal for home server, and control of your home devices such as cameras, printers,etc… In case your provider gave you the router without VPN support (which is my case) it is the perfect way to make your own VPN server.
As Apple has removed PPTP from IOS 10, L2TP + IPsec is one of the options. Here is my config that works perfectly on my iPhone and iPad. Raspberry Pi runs Raspbian Jessie.
(This setup should be the same on all linux platforms)
1. Forward udp ports 500 and 4500 on your router. You can also put your Pi in DMZ, so all ports will be exposed to internet.
2. Install openswan
apt-get install xl2tpd openswan ppp lsof
Note: Answer NO when asked if an X.509 certificate for this host can be automatically created or imported. This certificate can be created and imported later using:
3. Give your Pi static IP
nohook lookup-hostname interface eth0 static ip_address=192.168.0.166/24 static routers=192.168.0.1 static domain_name_servers=188.8.131.52
192.168.0.166 is my Raspberry Pi ip, and 192.168.0.1 is my router. You have to switch those to your ip addresses.
4. Firewall and IP forwarding
Execute those line by line. You have to be root, or you can use sudo.
iptables –table nat –append POSTROUTING –jump MASQUERADE
echo “net.ipv4.ip_forward = 1” | tee -a /etc/sysctl.conf
echo “net.ipv4.conf.all.accept_redirects = 0” | tee -a /etc/sysctl.conf
echo “net.ipv4.conf.all.send_redirects = 0” | tee -a /etc/sysctl.conf
for vpn in /proc/sys/net/ipv4/conf/*; do echo 0 > $vpn/accept_redirects; echo 0 > $vpn/send_redirects; done
Add this code to /etc/rc.local
for vpn in /proc/sys/net/ipv4/conf/*; do echo 0 > $vpn/accept_redirects; echo 0 > $vpn/send_redirects; done iptables --table nat --append POSTROUTING --jump MASQUERADE
This is whole config. Just replace 192.168.0.166 to your IP and 192.168.0.1 to your router IP
version 2.0 config setup nat_traversal=yes protostack=netkey virtual_private=%v4:192.168.0.0/16,%v4:10.0.0.0/8,%v4:172.16.0.0/12,%v4:184.108.40.206/8,%v4:!10.25$ oe=off plutodebug=all plutostderrlog=/var/log/openswan.log conn L2TP-PSK-NAT rightsubnet=vhost:%priv also=L2TP-PSK-noNAT conn L2TP-PSK-noNAT authby=secret pfs=no auto=add keyingtries=3 # we cannot rekey for %any, let client rekey rekey=no # Apple iOS doesn't send delete notify so we need dead peer detection # to detect vanishing clients dpddelay=30 dpdtimeout=120 dpdaction=clear # Set ikelifetime and keylife to same defaults windows has ikelifetime=8h keylife=1h # l2tp-over-ipsec is transport mode type=transport # left=192.168.0.166 # # For updated Windows 2000/XP clients, # to support old clients as well, use leftprotoport=17/%any leftprotoport=17/%any # # The remote user. # right=%any # Using the magic port of "%any" means "any one single port". This is # a work around required for Apple OSX clients that use a randomly # high port. rightprotoport=17/%any #force all to be nat'ed. because of ios forceencaps=yes # Normally, KLIPS drops all plaintext traffic from IP's it has a crypted # connection with. With L2TP clients behind NAT, that's not really what # you want. The connection below allows both l2tp/ipsec and plaintext # connections from behind the same NAT router. # The l2tpd use a leftprotoport, so they are more specific and will be used # first. Then, packets for the host on different ports and protocols (eg ssh) # will match this passthrough conn. conn passthrough-for-non-l2tp type=passthrough left=192.168.0.166 leftnexthop=192.168.0.1 right=0.0.0.0 rightsubnet=0.0.0.0/0 auto=route
Just put your IP address and your secret here.
include /var/lib/openswan/ipsec.secrets.inc 192.168.0.166 %any: PSK "your_password_here"
Put your IP here and set range that will not conflict with your router dhcp
[global] ipsec saref = yes listen-addr = 192.168.0.166 [lns default] ip range = 192.168.0.201-192.168.0.250 local ip = 192.168.0.166 assign ip = yes require chap = yes refuse pap = yes require authentication = yes name = linkVPN ppp debug = yes pppoptfile = /etc/ppp/options.xl2tpd length bit = yes
This one you can just copy.
require-mschap-v2 ipcp-accept-local ipcp-accept-remote ms-dns 220.127.116.11 asyncmap 0 auth crtscts lock idle 1800 mtu 1200 mru 1200 modem debug name l2tpd proxyarp lcp-echo-interval 30 lcp-echo-failure 4 nodefaultroute connect-delay 5000
Set your user and password here.
# Secrets for authentication using CHAP # client server secret IP addresses username * password *
10. Restart the service
And that is it. Make sure your VPN server starts on boot:
update-rc.d -f ipsec remove
update-rc.d ipsec defaults
Chose MS-Chap v2 when connecting
And put your IPsec secret here
On IOS 10
Windows does not support IPsec NAT-T by default, which is used whenever the server is behind a NAT (as in this case). You have to add a registry key to enable this.
On your Windows Vista, 7 or 8 client machine change or add the following registry item:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent\ New DWORD (32-bit) Value:AssumeUDPEncapsulationContextOnSendRule Set the value to 2
This allows the client or server to be behind a NAT firewall.