open-iscsi Cannot connect to my tgt target

Hi,

i am new at the iSCSI's wonderful world, So please ignore my noobness...

I wanted to install the tgt to my ARM NAS, So I had to compile the
source and create a package. That was successfull. :)

After it, I configured a target to a simple test environment, see here
(http://pastebin.com/u24gZ6JC).

But when I try to login, using open-iscsi on my Ubuntu 16.04v desktop,
it gives me the following error:

sudo iscsiadm -m node --login
Logging in to [iface: default, target: iqn.<secret>:<secret>, portal:
10.0.0.27,3260] (multiple)
iscsiadm: Could not login to [iface: default, target:
iqn.<secret>:<secret>, portal: 10.0.0.27,3260].
iscsiadm: initiator reported error (24 - iSCSI login failed due to
authorization failure)
iscsiadm: Could not log into all portals

What Can I Do?

Many thanks!