3.2 Configure Traffic Limits

In the next example we want to give our vhost www.example.com a traffic limit of 100MB per month, and if that limit is exceeded, we want to limit the download speed to 128kbps, max. 5 requests per second and max. 15 open connections:

<VirtualHost 1.2.3.4>
  ServerName www.example.com
  ServerAdmin webmaster@example.com
  DocumentRoot /var/www
  CBandLimit 100M
  CBandExceededSpeed 128 5 15
  CBandScoreboard /var/www/scoreboard
  CBandPeriod 4W
</VirtualHost>

The directives are pretty self-explanatory. The CBandPeriod directive specifies after what time the traffic counter is reset to 0.

The next example is pretty similar, but now we don't want the speed to be limited if the traffic is exceeded, no, we get more restrictive and deliver a 503 status page instead:

<VirtualHost 1.2.3.4>
  ServerName www.example.com
  ServerAdmin webmaster@example.com
  DocumentRoot /var/www
  CBandLimit 100M
  CBandScoreboard /var/www/scoreboard
  CBandPeriod 4W
</VirtualHost>

If you want to redirect the user to a URL instead of presenting a 503 error to him, you can do it like this:

<VirtualHost 1.2.3.4>
  ServerName www.example.com
  ServerAdmin webmaster@example.com
  DocumentRoot /var/www
  CBandLimit 100M
  CBandExceededURL http://www.someisp.com/traffic_exceeded.html
  CBandScoreboard /var/www/scoreboard
  CBandPeriod 4W
</VirtualHost>

Please note: the CBandExceededSpeed and the CBandExceededURL directives are mutually exclusive. They do not make sense in the same vhost!

After your changes, you must restart Apache:

Debian:

/etc/init.d/apache2 restart

Fedora:

/etc/init.d/httpd restart

Of course, you are free to combine the directives of chapter 3.1 and 3.2 in any way you like.

4 Status Page

To view the current bandwidth limits, usages, users, scoreboards, add the following Location lines to the vhost configuration:

<VirtualHost 1.2.3.4>
  ServerName www.example.com
  ServerAdmin webmaster@example.com
  DocumentRoot /var/www
  CBandLimit 100M
  CBandExceededSpeed 128 5 15
  CBandScoreboard /var/www/scoreboard
  CBandPeriod 4W

  <Location /cband-status>
    SetHandler cband-status
  </Location>
  <Location /cband-status-me>
    SetHandler cband-status-me
  </Location>
</VirtualHost>

Restart Apache, and afterwards you can find the status pages under http://www.example.com/cband-status and http://www.example.com/cband-status-me:

5 Links

• Apache Module mod_cband: http://cband.linux.pl/home
• ISPConfig and BandWidth control: http://e-corona.org/blog,245