title: ssh host key verification failed on one of the clients only
body: <p>I can't ssh from client "A" to server "B"  (but I can from many other ssh clients on the same subnet than "A" - all are *nux machines)</p>
  
  <p><strong>serverA>ssh -v -p PORT user@serverB</strong>  </p>
  
  <pre><code>OpenSSH_5.3p1 Debian-3ubuntu5, OpenSSL 0.9.8k 25 Mar 2009  
  debug1: Reading configuration data /etc/ssh/ssh_config  
  debug1: Applying options for *  
  debug1: Connecting to serverB [serverB] port PORT.  
  debug1: Connection established.  
  debug1: identity file /home/user_A/.ssh/id_rsa type -1  
  debug1: identity file /home/user_A/.ssh/id_dsa type 2  
  debug1: Checking blacklist file /usr/share/ssh/blacklist.DSA-1024  
  debug1: Checking blacklist file /etc/ssh/blacklist.DSA-1024  
  debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5  
  debug1: match: OpenSSH_5.1p1 Debian-5 pat OpenSSH*  
  debug1: Enabling compatibility mode for protocol 2.0  
  debug1: Local version string SSH-2.0-OpenSSH_5.3p1 Debian-3ubuntu5  
  debug1: SSH2_MSG_KEXINIT sent  
  debug1: SSH2_MSG_KEXINIT received  
  debug1: kex: server-&gt;client aes128-ctr hmac-md5 none  
  debug1: kex: client-&gt;server aes128-ctr hmac-md5 none  
  debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024&lt;1024&lt;8192) sent  
  debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP  
  debug1: SSH2_MSG_KEX_DH_GEX_INIT sent  
  debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY  
  debug1: checking without port identifier  
  Host key verification failed.  
  </code></pre>
  
  <p>I've already checked these following pts on client A - as server A looks to be the point - :  </p>
  
  <ul>
  <li>user_A/.ssh directory permissions : 700 (see man ssh)  </li>
  <li>user_A/.ssh/known_hosts permissions: 644 (see man ssh)  </li>
  <li>user_A/.ssh/known_hosts: does NOT content serverB host public key  </li>
  <li>otherusers/.ssh/known_hosts: does NOT content serverB host public key  </li>
  </ul>
  
  <p>I've tried :</p>
  
  <ul>
  <li>deleting known_hosts on server A: same error remains</li>
  <li>to empty known_hosts on server A: same error</li>
  <li>checking if host key names are matching the ssh server config: ok (HostKey /etc/ssh/ssh_host_rsa_key)    </li>
  <li>regenerating server B host keys (ssh-keygen -t dsa/rsa -f /etc/ssh/ssh_host_dsa/rsa_key) : same error  </li>
  <li>ssh -p PORT me@localhost on serverB: it also works as from other ssh clients  </li>
  </ul>
  
  <p>So I'm really stacked now ! ssh specialists welcome home.</p>
  
  <p>Thx in advance</p>