.... I installed it and it seems to be working well (Blocked 1096 requests with invalid UA so far) but my question is what is the recommended Minimum UA length number I should have entered? The default after the install is 10 but I wasn't sure if I should leave it there or change it?.....
Yes, sites with high traffic volumes will block many robots with invalid UA. Thanks for the feedback. I am happy to know that my plugin has been very effective on your site.
Here is the reason why I made this plugin --
- When there is an invalid UA (User Agent) header detected, the UA POLICE plugin will give the visitor (or robot) a clear warning and status about what is wrong (the error page). Some human visitors deliberately forge their UA in order to protect their privacy. When they see the error page, they can make switch to using a valid UA and visit your site as any other normal visitor. Unlike in Traffic Cop, the blocking in UA POLICE is NOT permanent! Also, UA POLICE is lightweight and uses less overhead than Traffic Cop (for validation of UA).
On my non-JobBoard sites, I use a setting of 34 characters minimum length. This higher value may potentially block some robots that you'd want to access your site. In my case, I am very, very restrictive about who can access my site.
Once the PRO version is out, you will be able to study the detailed logs and see if there were any false positives and adjust your settings accordingly. The PRO version will also have more advanced settings to better detect forged UA.
As I wrote, you may try increasing the minimum length setting up to 34, however, this higher setting will block requests from robots with the following UA:
Mozilla/5.0
Mozilla/5.0 (compatible)
The above UAs may be used by some legitimate robots. I recently discovered a visit from CAREERJET.NET robot which used UA
Mozilla/5.0 (compatible)
Best wishes,
Peter
How to forge UA (User Agent):