[Openswan Users] Route-based VPN

[Vincent Bernat]

Hello!

I would like to use OpenSWAN to get a VPN with several ISG 2000
appliances. Each of them is using a route-based VPN. This means that each
VPN has a virtual interface tunnel.X and we use route to explain what
should be encrypted in what VPN. In this case, left and right subnets are
advertised as 0.0.0.0/0.

Here is a working OpenSWAN setup:

conn XXXX
  auto=start
  right=193.XXXXXXXXX
  authby=secret
  left=81.XXXXXXX
  leftsubnet=0.0.0.0/0
  leftnexthop=%defaultroute
  rightsubnet=0.0.0.0/0
  rightnexthop=%defaultroute
  leftupdown=/custom/script

The /custom/script just puts some route to ipsec0 interface for networks
that should be encrypted.

Now, I would like to have a second VPN with the same instance of OpenSWAN.
Therefore, I would need an ipsec1 interface. It seems that I can only bind
an ipsecX interface to a physical interface. Can I bind it to the same
physical interface than ipsec0? Can I bind it to a labelled interface (like
eth0:1)?

I would like to use routes like this:
 ip route add net1 dev ipsec0
 ip route add net2 dev ipsec0
 ip route add net3 dev ipsec1
 ip route add net4 dev ipsec1