IPsec - sometimes connecting. Behind a firewall being an issue?


#1

Background:
End A: Balance One. Static IP
End B: Balance 20, behind a DSL modem with DHCP.
WAN on the B20 side: 10.0.0.0/24

Works:

  • PepVPN between the two Incl. providing access to 10.0.0.0/24 (by means of an outbound rule to the PepVPN connection) at the B20 end.

  • IPsec VPN (aggressive mode) between the two when the B20 does not offer 10.0.0.0/24 as a local net (and the B-One does name 10.0.0.0/24 as a remote network)

Does not work:

  • IPsec VPN between the two when the B20 does offer 10.0.0.0/24 as a local net (and the B-One does not name 10.0.0.0/24 as a remote network). I sometimes get a partially established connection, sometimes none at all.

Furthermore, the B20 reports the connection as being fully established, while the B-One claims it is being partially (or not at all) established. Screenshots attached.

Observation:
I have performed similar set-ups in the past, with an aggressive mode set-up with one end providing a WAN connection as local network (to ensure proper routing).

Any suggestions as to what can allow me to establish the IPsec (not PepVPN) connection appropriately?
Status at the B20:


Status at the B-one 9at the same time):

Setup at the B20:

Setup at the B-One: