There is a description of the problem I have stumbled across a while ago: http://lists.debian.org/debian-user/2007/05/msg02019.html Basically, I wasn't able to establish the SSH connection even to localhost.
I've finally figured out what had caused the problem. I ran sshd in debug mode and noticed "setreuid 100: Resource temporarily unavailable". The sshd user id is 100 in debian. It turned out that the setreuid(2) syscall has been failing for some reason. I wrote a simple test program (http://epsmu.com/~kuvkir/setreuid.c) to check that and it appeared that setreuid is failing for this particular uid (100). I'm not sure if it is a debian or an openssh specific issue, but rather glibc (2.3.6-ds1-13) or maybe kernel (2.6.18-4-powerpc debian) related thing. For now I has changed the sshd uid to another value and restared the ssh daemon and it works fine now. Thanks, Kirill
