IPSec Tunnel

January 7, 2022 | 1 min Read

IPSec Tunnel

# LAPTOP
cat /etc/ipsec.conf 
config setup

conn laptop
     authby=secret
     pfs=yes
     auto=start
     keyingtries=3
     dpddelay=30
     dpdtimeout=120
     dpdaction=clear
     ikelifetime=8h
     ikev2=no
     keylife=1h
     #phase2alg=aes128-sha1;modp1024
     #ike=aes128-sha1;modp1024
     type=tunnel
     left=%defaultroute
     leftsubnet=192.168.1.0/24
     leftid=88.212.33.167  # u mna doma verejna na routeri
     rightsubnet=172.31.0.0/20
     right=18.237.195.235   # EC2 v AWS

# AWS EC2
cat /etc/ipsec.conf.bavi 
config setup

conn aws-ec2
     authby=secret
     pfs=yes
     auto=start
     keyingtries=3
     dpddelay=30
     dpdtimeout=120
     dpdaction=clear
     ikelifetime=8h
     keylife=1h
     #phase2alg=aes128-sha1;modp1024
     #ike=aes128-sha1;modp1024
     type=tunnel
     ikev2=no
     right=88.212.33.167  # u mna doma verejna na routeri
     rightsubnet=192.168.1.0/24
     left=%defaultroute   # EC2 v AWS 
     leftid=18.237.195.235   # EC2 v AWS 
     leftsubnet=172.31.0.0/20

cat /etc/ipsec.secrets 
88.212.33.167 18.237.195.235 : PSK "..."

set route via ipsec tunnel node

run on other hosts in network

sudo ip r add  172.31.0.0/20 via 192.168.1.144 dev wlan0
ip r get 172.31.12.119

disable redirect to allow all hosts in network to access other network hosts

run on ipsec node

echo 0 | sudo tee /proc/sys/net/ipv4/conf/*/send_redirects

 
sudo ip r flush cache
openssl rand -hex 32

# Check this setting t your PC (laptop)
sysctl net.ipv4.ip_forward=1


cat  /etc/sysctl.d/97-vpn.conf 
net.ipv4.ip_forward = 1
net.ipv4.conf.all.send_redirects = 0


# 91.127.47.154 88.212.33.167 : PSK "a...22959da18"
%any : PSK "a...22959da18"


conn vpn
     authby=secret
     auto=start
     type=tunnel
     ikev2=insist

     left=%defaultroute
     leftsubnet=192.168.2.0/24
     leftid=88.212.33.167

     rightsubnet=192.168.1.0/24
     right=91.127.47.154

Jan Toth

I have been in DevOps related jobs for past 6 years dealing mainly with Kubernetes in AWS and on-premise as well. I spent quite a lot …