Chapter 156. Client does not support authentication protocol error

MySQL 4.1 uses an authentication protocal based on a password hashing algorithm that is incompatible with that used by older clients. If you upgrade the server to 4.1, attempts to connect to a it with an older client may fail with the following message:

shell> mysql
Client does not support authentication protocol requested
by server; consider upgrading MySQL client

To solve this problem you should do one of the following:

For background on password hashing and authentication, see Password hashing.