I am trying to deter bots from surfing my pages. So I want to force a login from all Ip Address that are not the top 4 search engines. Is this possible?
Have you considered using a robots.txt file to minimize unwanted traffic from automated spidering tools?
You can have multiple Disallow lines for each user agent (ie, for each spider). Here is an example of a longer robots.txt file:
User-agent: *
Disallow: /images/
Disallow: /cgi-bin/
User-agent: Googlebot-Image
Disallow: /
Here is an example that disallows everything except google
User-agent: *
Disallow: /
User-agent: Googlebot
allow: /
A word of warning: This method isn't guaranteed to stop disallowed agents from going through your site, it just asks them nicely in a standardized way that most of these tools understand.
Yes. You can force login for all your pages except for few ip addresses. It depends on what web server are you using and what kind of access control allowed?
if you want forced logind for everyone except the top 4 search engines, you could ask for login from everyone except the top 4 search engines or auto login them