When loading auth_ldap.so using LoadModule, Apache complains about not finding the __eprintf function and will not start. This happens when using certain combinations of Solaris, gcc, and the Mozilla LDAP SDK. The solution is to add "-DNEED_EPRINTF" to the EXTRA_CFLAGS line in the Makefile and recompile. On Solaris 2.5.1 and Netscape's LDAP SDK with SSL (libldapssl30.so) Apache doesn't start, but nothing seems to get logged to the error log. Apache is dumping core after a call to dlclose. This only occurs on Solaris 2.5.1 when using Netscape's libraries. It appears to be a bug with dld on Solaris 2.5.1. One solution is to upgrade to Solaris 2.6 or later. If that isn't possible, another workaround is to ensure that auth_ldap is the first module loaded using the LoadModule directive. This can cause problems if you would prefer that auth_ldap takes precedence over other auth modules, since normally the last module loaded gets called first. You can solve this by adding a ClearModuleList directive, then issuing AddModule directives for every loaded module, in reverse order that you want them called. Do this after the last LoadModule directive.