Description:

PHREL is a Per Host RatE Limiter written in C to efficiently track the rate
of incoming traffic on a per host basis and insert a chain into iptables when
a configured threshold is crossed. The inserted chain may either rate limit
or completely block the offending host for a period of time and will be
automatically removed when the offending host's traffic levels return to
normal. PHREL can be used with any type of traffic, but it is particularly
well suited to protecting name servers from random hosts that flood DNS
requests and preventing SSH brute force login attempts.

PHREL now supports IPv6 and syncronization between instances of PHREL via a
MySQL database. The syncronization feature is designed to work in load
balanced server farm environments or to simply provide database access to the
hosts that PHREL is currently monitoring.