[Openswan Users] Multiple servers with multiple tunnels each

[Neal Murphy]

What you described should work, with a couple caveats:
  - Your config is missing host2-host3, host2-host4, and host3-host4
  - Be sure that each of the four sites uses unique LAN addressing. That is,
    you cannot (easily) use 10.10.10.0/24 at two sites.
You should be able to copy a single set of files (config, secrets, etc.) to 
each site.

> From: David Brezynski <brezy at u.washington.edu>
> Subject: Multiple servers with multiple tunnels each
> Date: June 23, 2014 at 3:01:50 PM EDT
> To: users at lists.openswan.org
> 
> 
> Hi List
> 
> I'm working on an IPSEC solution for a number of servers (lets say 4) where
> I need to encrypt traffic between each server (so each servers needs a
> tunnel to the other 3) for a distributed application.  Traffic should not
> be encrypted between these servers and any others on the network.  All IPs
> are static.
> 
> I'm assuming my only option is to set up individual tunnels in a one to
> many relationship for each of the servers (see configuration below).
> 
> Question - is this the correct approach?  Is there more concise
> configuration I can use so I can reuse the configuration files unchanged
> on all the servers involved?  Anything I'm missing?
> 
> In the initial setup I'm using pre-shared keys and my config files
> (connection definitions and secrets file) are:
> 
> 
> ============ /etc/ipsec.d/test.con
> conn host1-to-host2
>   left=host1
>   right=host2
>   auto=start
>   authby=secret
> 
> conn host1-to-host3
>   left=host1
>   right=host3
>   auto=start
>   authby=secret
> 
> conn host1-to-host4
>   left=host1
>   right=host4
>   auto=start
>   authby=secret
> 
> ======================
> 
> 
> ============ /etc/ipsec.d/ipsec.secrets
> host1 host2 : PSK "key in quotations"
> host1 host3  : PSK "key in quotations"
> host1 host4  : PSK "key in quotations"
> ========================
> 
> Thanks
> David