[asterisk-users] howto configure an asterisk to send credentials in a REGISTER message to another asterisk

[Imanol Pardavila]

Hi,
I am trying to register an asterisk (Asterisk 1) against another one 
(Asterisk 2). My problem is that the REGISTER message goes without 
credentials and the Asterisk 2 send a 401 message to the Asterisk 1.
How can I configure Asterisk 1 to force it to send credentials? I have 
tried setting Asterisk 2's IP in the "realm" field of Asterisk's 1 
sip.conf, but it doesn`t work.
Any ideas?
Thanks
Regards