Friends..Please clarify my question related to SSH:

An SSH server will always publicize its public key to any computer which contacts via SSH. Please let me know how this happens..
Suppose I am performing an SSH from A to B for the first time, even before authentication through password is done, the client computer tells me the finger print of the server is "so and so..." and authentication could not be established...Actually the public key of the server is in /etc/ssh directory(ssh_host_rsa/dsa_key.pub), so how the client access the /etc/ssh directory...? or how the server publicize the key to the clients...please let me know this. Thank u...

There is a wealth of information on the inner workings of ssh on the internet. One that may be a good read for you is:

http://en.wikipedia.org/wiki/Ssh

Have fun,
Fordeck

The public key is simply transmitted accross the network from the server to the client. The SSH client connects to the server on port 22 (or whaqtever port sshd is running on) and then the server sends the key over the TCP network socket. There is no need for the client to access any files on the remote system for key exchange; the sshd server software does that. Likewise, the ssh server need not access key files on the client system -- the client will send the relevant ones over the network link.

Thank u friends..