What Does Hammering Mean?
Hammering refers to the automated processes of repeatedly trying to connect to different types of servers such as email, file transfer, etc., which are unavailable or busy with other tasks.
Hammering usually tends to slow down the server operation, making it difficult for additional users to establish a new connection successfully. It is analogous to repeatedly pressing the redial button for a telephone number already busy with another call, and not waiting until the line becomes available.
Techopedia Explains Hammering
When an FTP server is contacted over and over again within a short span of time, it is referred to as hammering. Generally, the server used for trading purposes has a limited number of active available connections. When the server receives an unlimited number of connection requests, access will simply be denied until it becomes free. The act of repeatedly trying to contact the server also consumes bandwidth, thereby slowing down access to the server. Already running at full capacity, the server has to send a busy message in response to the device trying to connect, which will further slows down the server.
Some FTP servers allow users to retry only at specific intervals to avoid hammering. The time is generally set to 120 seconds between each hammer attempt. Some FTP sites also check for devices responsible for hammering. If detected, the server may block access to the offending IP address or subnet, either temporarily or permanently.