Subnet to subnet VPN

Building a tunnel between two endpoints for multiple subnets is pretty simialar to a host to host VPN tunnel. Except you will see we are adding leftsubnets/rightsubnets statements:

# /etc/ipsec.conf
# The version is only required for openswan
version 2

config setup
    nat_traversal=yes
    protostack=netkey

conn mysubnet
     also=mytunnel
     leftsubnet=192.0.1.0/24
     rightsubnet=192.0.2.0/24

conn mysubnet6
     also=mytunnel
     connaddrfamily=ipv6
     leftsubnet=2001:db8:0:1::/64
     rightsubnet=2001:db8:0:2::/64

conn mytunnel
    leftid=@west
    left=192.1.2.23
    leftrsasigkey=0sAQOrlo+hOafUZDlCQmXFrje/oZm [...] W2n417C/4urYHQkCvuIQ==
    rightid=@east
    right=192.1.2.45
    rightrsasigkey=0sAQO3fwC6nSSGgt64DWiYZzuHbc4 [...] D/v8t5YTQ==
    authby=rsasig
    # use auto=start when done testing the tunnel
    auto=add