[strongSwan] How to select a specific conn

[Robert Dahlem]

Hello,

I'm totally new to strongSwan. I am running strongSwan 5.5.1 on Debian
Stretch. As a first step I set up a test scenario with IKEv1 and PSK in
my private network. strongSwan is at 192.168.1.15

/etc/ipsec.secrets:
	192.168.1.15 : PSK "totallysecret"
	dahlem : XAUTH "secrettoo"

/etc/ipsec.conf
	config setup
		uniqueids=never
	conn %default
	        compress=no
	        dpdaction=clear
	conn vpnserver
	        auto=add
	        leftauth=psk
	        rightauth=psk
	        rightauth2=xauth
	        rightsourceip=172.28.1.0/24

The client is an Android device in 192.168.1.0/24 with these settings:
	Type: IPSec Xauth PSK
	Server address: 192.168.1.15
	IPSec identifier: (not used)
	IPSec pre-shared key: totallysecret
	Username: dahlem
	Password: secrettoo

Everything works fine so far. Now I would like to introduce a second
configuration, lets say:

	conn vpnserver2
	        [...]
	        rightsourceip=172.28.2.0/24

How do I get the client to choose that second configuration? I could
probably use the "IPSec identifier", but that would force me to enable
aggressive mode, which seems to be frowned upon.

And how do I get the server to use a different PSK? In other words: what
makes the connection between something in "conn" and a specific entry in
ipsec.secrets?

Kind regards,
Robert