HTTP user agent
There are some packet filtering products that block requests that use Nmap's default HTTP user agent. You can use a different HTTP user agent by setting the http.useragent argument:
$ nmap -p80 --script http-methods --script-args http.useragent="Mozilla 42" <target>
HTTP pipelining
Some web servers allow the encapsulation of more than one HTTP request in a single packet. This may speed up the execution of an NSE HTTP script, and it is recommended that it is used if the web server supports it. The http library, by default, tries to pipeline 40 requests and auto-adjusts the number of requests according to the traffic conditions, based on the Keep-Alive header:
$ nmap -p80 --script http-methods --script-args http.pipeline=25 <target>
Additionally, you can use the http.max-pipeline argument to set the maximum number of HTTP requests to be added to the pipeline. If the http.pipeline script parameter is set, this argument will be...