I've set up Apache to send requests to camera.example.com to an a webcam accessible via an IP address not associated with the server Apache's running on, using ProxyPass:
[camera] -- [nat / prt frwrd] -- [11.22.33.44]-- [internets] -- [webserver]
Relevant entry in the Apache's virtual host directive for the 'example.com':
<VirtualHost *>
ServerName camera.example.com
ProxyRequests Off
ProxyPass / http://11.22.33.44/
ProxyPassReverse / http://11.22.33.44/
</VirtualHost>
Works like a charm, however, the camera is not always turned on. In that case, instead of having Apache serve a 'not found' error upon visiting my camera , I'd like it to serve an alternative web page.
Would it be possible to set some sort of 'fall-back' address in case the first one (the camera's) is not available?