BlockSync Project

Welcome to the BlockSync Project

This project aims to provide an efficient way to provide mutual protection from deemed bad actors that attack Internet facing servers. The result will be an open source set of communication tools that use established protocols for high speed and light weight transmission of attacker information to a variable number of targets (unicasting to a possibly large number of hosts).


There are many open source firewall technologies in widespread use, most based on either packet filter (pf) or netfilter (iptables). There is much technology that provides network clustering (for example, OpenBSD’s CARP and pfsync; netfilter; corosync and pacemaker), however it’s difficult for disparate (loosely coupled) servers to communicate the identity of attackers in real time to a trusted community of (tightly coupled) peers. Servers or firewalls that use state-table replication techniques, such as pfsync or netfilter, have a (near) real-time view of pass/block decisions other members have made. There needs to be a mechanism for loosely coupled servers to share block decisions in a similar fashion.

Our goal is to create an open source tool for those of us that have multiple Internet facing servers to crowd source information that will block attackers via the firewall technology of choice (OpenBSD/FreeBSD pf/pfSense, iptables, others).

Project Page

All project files are still private yet, but when we publish to GitHub or SourceForge, this section will be updated.


We have published a GoFundMe page to acquire more lab equipment here at

Soekris net5501 SBC Linux installation

Soekris Engineering net5501 SBC setup with Linux


net5501 is a x86 SBC that I ordered with 4 10/100 ethernet ports, 512MB memory, 500MHz Geode LX CPU

Serial console is used for setup of net5501 – BIOS writes to serial port since there is no xVGA port. <ctrl-p> to enter BIOS setup. DB9 pinout:

2 — 3

3 — 2

5 — 5

Use 19,200 bps 8 data bits, no parity, 1 stop

With the Macbook Pro, I use a Keyspan USA-19HS USB <–> DB9 RS232 serial converter (and DB9-RJ45 adapters to implement the null modem configuration and allow me to use an ethernet cable for the serial console <–> Keyspan device.

On OS X (10.5) I use “screen” to provide the serial terminal interface:

$ screen /dev/tty.USA19H1a2P1.1 19200,8

<ctrl-a><ctrl-\> to exit

On the net5501 BIOS, PXEBoot is disabled:

set PXEBoot=Disabled

I setup voyage-0.5.0 on a compact flash card then installed the card into the net5501 – works great the first boot

Default root info: root / voyage

OpenBSD setup info: