ssh - connection closed by remote host

[Frode Nilsen]

hi list,

I have a little problem with one of my servers; the server is FC1, using
LDAP for user information, and Kerberos for user authentication, and
OpenAFS for distributed filesystem. And all packages are of the latest
stable release.

The problem occured for the first time 2 weeks ago; the problem shows
itself when I try ssh'ing with a user from the ldap/kerberos-database,
and I get a "connection closed by remote host"-message. When I try to
ssh into my server with a user from the  local passwd file, I have no
problems.

Using "ssh -vv"  I get this after password input:

debug2: we sent a password packet, wait for reply
debug1: Authentication succeeded (password).
debug1: channel 0: new [client-session]
debug2: channel 0: send open
debug1: Entering interactive session.
debug2: callback start
debug2: ssh_session2_setup: id 0
debug1: channel 0: request pty-req
debug2: x11_get_proto: /usr/X11R6/bin/xauth list :0.0 2>/dev/null
debug1: Requesting X11 forwarding with authentication spoofing.
debug1: channel 0: request x11-req
debug1: channel 0: request shell
debug2: callback done
debug1: channel 0: open confirm rwindow 0 rmax 32768
debug1: channel_free: channel 0: client-session, nchannels 1
Connection to ************* closed by remote host.
Connection to ************* closed.
debug1: Transferred: stdin 0, stdout 0, stderr 89 bytes in 0.6 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 137.0
debug1: Exit status -1


In the "/var/log/messages"-file, it says:

Aug  3 03:28:29 oliven sshd(pam_unix)[1573]: check pass; user unknown
Aug  3 03:28:29 oliven sshd(pam_unix)[1573]: authentication failure;
logname= uid=0 euid=0 tty=NODEVssh ruser= rhost=******.cm.chello.no
Aug  3 03:28:29 oliven sshd[1573]: pam_krb5[1573]: authentication
succeeds for '********' (***************)
Aug  3 03:28:29 oliven sshd(pam_unix)[1575]: session opened for user
******** by (uid=1000)


So far as I understand the debugging and the log, the authentication
part succeeds, and after that the connection just closes. So I don't
think it is kerberos or ldap that's the problem (mostly because the
kerberos/ldap configuration has worked nicely for 2 months before this
problem occured), but more likely it has something to do with ssh and
pam, but I'm not able to figure this one out by myself.


Regards, Frode