how to examine ssh problem

[lina <lina.lastname@gmail.com>]

Hi,

when I tried to ssh some_server, it showed me,

Permission denied (publickey,gssapi-with-mic,password).

1] I tried ssh from desktop, laptop and other server, the same problem.
2] I generate a new key  by ssh-keygen in some_server, it still has
this problem.

I can ssh by username@full_some_server_address, but can't access in a
simple way,

Thanks for any advice,

-- 
Best Regards,

lina