LimitRequestLine directive

Syntax: LimitRequestLine bytes
Default: LimitRequestLine 8190
Context: server config
Status: core
Compatibility: LimitRequestLine is only available in Apache 1.3.2 and later.

This directive sets the number of bytes from 0 to the value of the compile-time constant DEFAULT_LIMIT_REQUEST_LINE (8190 as distributed) that will be allowed on the HTTP request-line.

The LimitRequestLine directive allows the server administrator to reduce the limit on the allowed size of a client's HTTP request-line below the normal input buffer size compiled with the server. Since the request-line consists of the HTTP method, URI, and protocol version, the LimitRequestLine directive places a restriction on the length of a request-URI allowed for a request on the server. A server needs this value to be large enough to hold any of its resource names, including any information that might be passed in the query part of a GET request.

This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.

For example:

LimitRequestLine 16380

Under normal conditions, the value should not be changed from the default.