Hello All I want to use apache-2.2.14 web server as a transparent proxy in ip layer on freebsd-7.0. I configured it with following scenario: Client1 Apache TProxy Configured web server 172.20.13.43 ---------------- [em0:172.20.13.196, 192.168.100.101:em1] --------------------192.168.100.102 My httpd.conf on Tproxy is: .... Listen 4129 <VirtualHost 172.20.13.196:4129> ServerName 172.20.13.196 ProxyRequests off ProxyTProxy On ProxyPass / http://192.168.100.102/ ProxyPassReverse / http://192.168.100.102/ ProxyPreserveHost On </VirtualHost> I used ipnat for trrafic redirection by following configuration. /etc/ipnat.conf: rdr em0 192.168.100.102/32 port 80 -> 172.20.13.196 port 4129 tcp when i request http://192.168.100.102 on web client1, i recieve following error on web browser: Service Temporarily Unavailable The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later. My apache error log is: [Sat Oct 15 11:59:45 2011] [debug] mod_proxy_http.c(56): proxy: HTTP: canonicalising URL //192.168.100.102/ [Sat Oct 15 11:59:45 2011] [debug] proxy_util.c(1494): [client 172.20.13.43] proxy: http: found worker http://192.168.100.102/ for http://192.168.100.102/ [Sat Oct 15 11:59:45 2011] [debug] mod_proxy.c(993): Running scheme http handler (attempt 0) [Sat Oct 15 11:59:45 2011] [debug] mod_proxy_http.c(1940): proxy: HTTP: serving URL http://192.168.100.102/ [Sat Oct 15 11:59:45 2011] [debug] proxy_util.c(1999): proxy: HTTP: has acquired connection for (192.168.100.102) [Sat Oct 15 11:59:45 2011] [debug] proxy_util.c(2055): proxy: connecting http://192.168.100.102/ to 192.168.100.102:80 [Sat Oct 15 11:59:45 2011] [debug] proxy_util.c(2153): proxy: connected / to 192.168.100.102:80 [Sat Oct 15 11:59:45 2011] [error] (22)Invalid argument: proxy: *error binding *to socket 172.20.13.43:4536 [Sat Oct 15 11:59:45 2011] [debug] proxy_util.c(2017): proxy: HTTP: has released connection for (192.168.100.102) How i can fix it? Any help would be great. -- Best regards Dariush Zahedmanesh