Stockade is a TCP-layer blocking tool written in
C++. It denies TCP/IP access to registered
IP address
An Internet Protocol address (IP address) is a numerical label such as that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...
es by using the
ipfw packet filter. It targets spam prevention, but may also be used against other attackers (e.g. brute force
password crackers.)
The rate limiting approach
This approach leverages the superior determination exhibited by legitimate senders. In this respect, it may be considered similar to
greylisting. Originally, the authors conceived an ''MT Proxy'' to rate-limit the
SMTP
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typi ...
connections of messages believed to be spam. That worked by adding a ''dummynet'' rule for frequent senders who had been sending messages that triggered an unreliable statistical analysis.
A key limitation of the original scheme was the consumption of local resources (in the SMTP proxy). Stockade approach introduces the notion that an inbound TCP connection may be rejected with some random probability proportional to the level of spam already seen from the connection’s originator over some configurable period of time.
That probability is subject to a ''decay'', configured as a halving time period, so that each IP address is eventually rehabilitated. That way, stockade provides for fully automatic spam mitigation.
See also
*
Fail2ban
Fail2Ban is an intrusion prevention system, intrusion prevention software framework. Written in the Python (programming language), Python programming language, it is designed to prevent brute-force attacks. It is able to run on POSIX systems that ...
is a generic intrusion prevention system, featuring multiple blocking techniques and preconfigured for a variety of server applications.
*
DenyHosts
DenyHosts is a log-based intrusion-prevention security tool for SSH servers written in Python. It is intended to prevent brute-force attacks on SSH servers by monitoring invalid login attempts in the authentication log and blocking the originatin ...
is a similar tool, specific for thwarting
SSH
The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution.
SSH was designed for Un ...
server attacks.
References
{{DEFAULTSORT:Stockade (Software)
Computer security software
Anti-spam
Free security software