Hi, I'm new to this list so I searched the archives first but didn't find the solution. I'm trying to setup an OWA 2003 with an apache (2.0.53) reverse proxy. (apparently many people on this list are doing so). This is my setup (please note that HTTP is used in the lan). Client on the Internet<--HTTPS-->Apache reverse proxy<---HTTP-->OWA on LAN With my current configuration browser based owa and active sync work, however RPC-HTTPS doesn't. I.e. it takes a very longtime (5 till 15 minutes) to sync. Ultimately a sync is made, however this isn't usable in production. So it seems for some reason time-outs happen. I activated both basic and windows authentication and ssl offloading on the IIS (alow basic authentication without http by adding a registry key). In my outlook profile basic authentication is set. Part of the apache config is shown below. I tried two other setups to check my IIS config: * Using a port forwarding instead of a reverse proxy: setup works within seconds * force http RPC while client is in network of IIS using windows authentication : this also works fine * force httpS RPC while client is in network of IIS using basic authentication : this also works fine ( outlook forces you to use HTTPS when using basic authentication) So it seems the IIS is setup correctly (only the ssl offloading isn't tested) Dumping traffic while using the reverse proxy and basic authentication show RPC errors (a digit/alpha character set), however none of them are listed or mentioned anywhere. Surfing to https://public/rpc/rpcproxy.dll also gives an error, but certificates are accepted fine ( added as trusted). I'm more or less out of option on this issue. Has anyone an idea why this won't work? And is it correct that NTLM (windows) authentication need a keepalive connection to function properly? As I noticed in my dumps the keepalives are not send while using the reverse proxy (although it is configured in the config , see below). Perhaps a bigger question : what is needed to let NTLM work through an apache reverse proxy? Please find below a part of the conf part of apache . Kind regards, Pieter <<<<>>> ...... Timeout 300 KeepAlive On MaxKeepAliveRequests 100 KeepAliveTimeout 15 LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_http_module modules/mod_proxy_http.so LoadModule proxy_ftp_module modules/mod_proxy_ftp.so LoadModule ssl_module modules/mod_ssl.so UseCanonicalName Off HostnameLookups Off ServerTokens Prod ServerSignature Off ProxyVia Off # The following directive disables redirects on non-GET requests for # a directory that does not include the trailing slash. This fixes a # problem with Microsoft WebFolders which does not appropriately handle # redirects for folders with DAV methods. # Same deal with Apple's DAV filesystem and Gnome VFS support for DAV. # BrowserMatch "Microsoft Data Access Internet Publishing Provider" redirect-carefully BrowserMatch "^WebDrive" redirect-carefully BrowserMatch "^WebDAVFS/1.[012]" redirect-carefully BrowserMatch "^gnome-vfs" redirect-carefully ..... <VirtualHost 195.0.83.244:443> SSLEngine on SSLCertificateFile /ub/conf/data/Appfw/owa2cert.pem SSLCertificateKeyFile /ub/conf/data/Appfw/owa2key.pem RequestHeader set Front-End-Https "On" ProxyRequests Off ProxyPreserveHost On RewriteEngine On ...... # enable Reverse re-writing ProxyPass / http://w2003sbs.domaion.be:80/ ProxyPassReverse /azerty http://w2003sbs.domain.be:800/azerty ..... </VirtualHost> -- --------------------------------------------------- Able: 1996-2006: already 10 safe years in YOUR company! aXs GUARD has completed security and anti-virus checks on this e-mail (http://www.axsguard.com) --------------------------------------------------- Able NV: ond.nr 0457.938.087 RPR Mechelen --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. See <URL:http://httpd.apache.org/userslist.html> for more info. To unsubscribe, e-mail: users-unsubscribe@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx