Zope 2.11, Python 2.4 The authentication issue has been resolved. Our Zopes run with Pound as a reverse proxy front-end. Current versions of Pound demand conformity to the http protocol which ZSyncer violates. The error returned was interpreted incorrectly as an Authentication Error. Connecting directly within the subnet resolved that problem. Now there is another problem. My setup has at the source machine has user:pass@<target-url><target-port>/zsyncerinstance as the destination and selects the ConnectionMgr and relative paths. The user:pass is a special user for transfers and has Manager permissions. In our setup, the zsyncerinstance is in the root directory so it should make no difference. Experimentally, it makes no difference--unchecking the relaive feature throws the same error. "Sync" throws an error with a traceback: # EOFError # # Traceback (most recent call last): File "/opt/Zope2.11/lib/python/DocumentTemplate/DT_Try.py", line 149, in render_try_except result = render_blocks(self.section, md) File "/opt/Zope2.11/lib/python/DocumentTemplate/DT_Util.py", line 196, in eval return eval(code, d) File "", line 0, in ? File "/opt/zope/zinstances/xxx/Products/ZSyncer/ZSyncer.py", line 438, in manage_compare include_base=1) File "/opt/zope/zinstances/xxx/Products/ZSyncer/ZSyncer.py", line 991, in _compare_path dest_base_info, dest_sub_info = self._getRemoteList(remote, path) File "/opt/zope/zinstances/xxx/Products/ZSyncer/ZSyncer.py", line 1211, in _getRemoteList return serverconn.manage_listObjects(path) File "/opt/zope/zinstances/xxx/Products/ZSyncer/ConnectionMgr.py", line 183, in __call__ ok,rd = cPickle.loads(data) EOFError which has me baffled. Any suggestions? Other folks have been using ZSyncer without problems on Zope 2.11. Dieter, you contributed the ConnectionMgr patch -- do you have any idea where things might be failing?