How do I hide ssh number from clients? When I type the following command it displays server version number to end users:
ssh -v server2.example.com OpenSSH_5.3p1 Debian-3ubuntu4, OpenSSL 0.9.8k 25 Mar 2009 debug1: Reading configuration data /home/vivek/.ssh/config debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to server2.example.com [123.x.y.z] port 22. debug1: Connection established. debug1: identity file /home/vivek/.ssh/identity type -1 debug1: identity file /home/vivek/.ssh/id_rsa type 1 debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048 debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048 debug1: identity file /home/vivek/.ssh/id_dsa type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3 debug1: match: OpenSSH_4.3 pat OpenSSH_4* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.3p1 Debian-3ubuntu4
telnet server2.example.com 22 Trying 123.x.y.z... Connected to v.txvip1. Escape character is '^]'. SSH-2.0-OpenSSH_4.3
Why does OpenSSH server report its version to clients?
Recently, my desktop hard disk crashed. So I reinstalled Linux and created a new set of private RSA keys for authentication. However, two of my remote UNIX servers still uses old DSA keys. I do not remember root password for those servers. I do have backup of private and public DSA keys and currently stored in /backup/home/user/.ssh/id_dsa and /backup/home/user/.ssh/id_dsa.pub. How do I force my ssh clients to use identity file /backup/home/user/.ssh/id_dsa to get back to my remote UNIX servers?