For SEO, you must be sure to grant permission against search engine
bots or crawlers such as google, yahoo and being while shut out the bad bots.
This feature is possible to fulfill your wishes by giving a pair of
“UA string” and “Qualification” separated by an applicable rule which
can be “
:” (pass) or “
UA string : [ ! ] Qualification
UA string # [ ! ] Qualification
You can specify a part of user agent string (case sensitive). An asterisk “
matches all user agents.
Currently, you can obtain 7 types of qualification listed bellow:
|FEED||True if the request is the feed url.|
|HOST||True if the result of host name is available.|
|HOST=string||True if the host name includes string.|
|REF=string||True if the HTTP referer includes string.|
|Country code||True if the request comes from the specified country.|
|IP address (CIDR)||True if the IP address is within the specific range.|
|AS number||True if the AS number is matched.|
The host name
HOST corresponding IP address will be retrieved via DNS reverse
lookup which is disabled by default.
A negative operation “
!” can be placed just before a qualification. It inverts
the meaning of qualification.
DNS reverse lookup will attempt to fetch a dns PTR record for an IP address. Its cost against the server’s resources is relatively high. For example, the following picture shows the result of 1st and 2nd time which is available at “Installation information” in “Plugin settings” section. It means that the fetched result would be cached in your server.
If “DNS reverse lookup” is disabled, then
always return true. For example,
Google:HOST would be converted to
Google:*. In this case, only user agent string would be checked. If the
converted result is one of
*#!*, it would be
|*:2620:101:4000::/42||Pass if an IP address is within the range.|
|Google:HOST||Pass if UA includes “Google” and host name is available.|
|Google#!HOST||Block if UA includes “Google” and host name is unavailable.|
|Yandex#*||Block if UA includes “Yandex”.|
|*#HOST=amazonaws||Block all UA if host name includes “amazonaws”.|
xyz-bot#HOST, then all the bots will be passed whose user agent string includes "bot" and its host name is available.