SVN update authentication request on some directories

When I issue svn update command on directories with the same user and group permissions, sometimes I get password prompt and sometimes I don't. How can I go about debugging t开发者_StackOverflowhis? What triggers such authentication on what seems to me directories with same permissions?

thanks!

Put your username/password (your svn account) directly into the command line:

svn --username <> --password <> update

With svn+ssh protocol the ssh component will ask you for the password.
How to setup ssh that it will not ask for a password.