- Red Hat Enterprise Linux 4, 5, 6
Error messages in
Oct 11 04:02:44 hostname sshd: Accepted publickey for <user> from ::ffff:192.168.0.1 port 22545 ssh2 Oct 11 04:02:44 hostname sshd: Postponed publickey for <user> from ::ffff:192.168.0.1 port 22546 ssh2
This issue occurs often with Oracle.
postponed public key can be eliminated by identifying the unwanted auth type(s) being tried before
publickey and disable them, either from the client side or the server side. In this case the unwanted method is
GSSAPIAuthentication, therefore we should disable the parameter on the client side.
Change the configuration in
Host * GSSAPIAuthentication yes
Host * GSSAPIAuthentication no
By disabling the
GSSAPIAuthentication method the
publickey method will not be postponed.
aliceis accessing the server via SSH, but before the public key is accepted it tries with other methods of authentication (
publickey,gssapi-with-mic,password), first tries with
gssapi-with-mic, then will try
publickey, and eventually
gssapi-with-micfails creating a delay on using the public key, therefore the message appears in the logs. Finally the right method is allowed (
publickey) and the session starts.
In order to debug SSH, to see what is causing the slow key exchange, and therefore the
postponed public key error message, the following can be done:
On the client:
1. Execute the command
script in the shell in order to capture some output:
$ script /tmp/SSHclient
2. Start the connection to the remote server with verbose mode on:
$ ssh -vvv userx@hostname
3. Once the connection is established, the connection can be closed and exit
script (control + d to close the connection, enter exit on the client to stop logging with
/tmp/SSHclient can be found on the client.
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