Hello,

finally i could solve the problem.

The log message shows that the problem comes from xinetd and not from
firebird itself. ( i saw this a too late )

Dec 28 16:45:59 hellbase xinetd[23734]: FAIL: gds_db address
from=192.168.0.1

So it seems xinetd with Gentoo blocks everything that is not explicit
allowed. Adding this line in the firebird configuration file for
xinetd (/etc/xinetd.d/firebird) solved the problem:

"only_from = 192.168.0.0/24"

Maybe this is helpful for somebody.

Thank you and best regards

Nils