SETTING UP PUTTY FOR MAC SOFTWARE
SETTING UP PUTTY FOR MAC MAC

You should contact your server's administrator and see whether they expect the host key to have changed.

SETTING UP PUTTY FOR MAC SOFTWARE

On the other hand, it may simply mean that the administrator of your server has accidentally changed the key while upgrading the SSH software this shouldn't happen but it is unfortunately possible. This may mean that a malicious attacker has replaced your server with a different one, or has redirected your network connection to their own machine. This message, followed by 'The server's host key does not match the one PuTTY has cached in the registry', means that PuTTY has connected to the SSH server before, knows what its host key should be, but has found a different one.

10.2 'WARNING - POTENTIAL SECURITY BREACH!' See section 2.2 for more information on host keys. You should verify the correctness of the key as before. SSH protocols 1 and 2 use separate host keys, so when you first use SSH 2 with a server you have only used SSH 1 with before, you will see this message again. If you see this message and you know that your installation of PuTTY has connected to the same server before, it may have been recently upgraded to SSH protocol version 2. You should attempt to verify the host key by other means, such as asking the machine's administrator. If you see this message, it means that PuTTY has not seen this host key before, and has no way of knowing whether it is correct or not.

Every server identifies itself by means of a host key once PuTTY knows the host key for a server, it will be able to detect if a malicious attacker redirects your connection to another machine. This error message occurs when PuTTY connects to a new SSH server. 10.1 'The server's host key is not cached in the registry' If you get an error message which is not listed in this chapter and which you don't understand, report it to us as a bug (see appendix B) and we will add documentation for it. We do not attempt to list all error messages here: there are many which should never occur, and some which should be self-explanatory. This chapter lists a number of common error messages which PuTTY and its associated tools can produce, and explains what they mean in more detail. Section 10.16: 'Network error: Connection timed out'.Section 10.15: 'Network error: Connection refused'.Section 10.14: 'Network error: Connection reset by peer'.Section 10.13: 'Network error: Software caused connection abort'.Section 10.12: 'Authentication failed at PuTTY X11 proxy'.Section 10.11: 'Incoming packet was garbled on decryption'.

SETTING UP PUTTY FOR MAC MAC

Section 10.10: 'Incorrect CRC received on packet' or 'Incorrect MAC received on packet'.

Section 10.9: 'Access denied', 'Authentication refused'.

Section 10.8: 'Server refused our public key' or 'Key refused'.

Section 10.7: 'Internal error', 'Internal fault', 'Assertion failed'.

Section 10.5: 'Server sent disconnect message type 2 (SSH_DISCONNECT_PROTOCOL_ERROR): 'Too many authentication failures for root''.

Section 10.4: 'The first cipher supported by the server is.

Section 10.3: 'Out of space for port forwardings'.

Section 10.2: 'WARNING - POTENTIAL SECURITY BREACH!'.

Section 10.1: 'The server's host key is not cached in the registry'.

Setting up putty for mac