Need Firewall to Forward

The firewall system might not be set to do forwarding.

Analysis of the problem
What works

Every box seems to be able to communicate with every address on the firewall, and the firewall seems to be able to communicate with every address.

What's broken

However, with the exception of communications involving one of the IP addresses that are on the firewall itself, none of the devices seems to be able to communicate from one subnet to another subnet.

Solution

Enable forwarding.

Enable forwarding in OpenBSD

First, back up this file:

sudo cpytobak /etc/sysctl.conf

(e.g...)

user@ttyC0:firewall:~/$ sudo cpytobak /etc/sysctl.conf

After this section that is specific to this operating system, this guide provides a reference to information about how to enable traffic forarding. Skip the parts about backing up the /etc/sysctl.conf file, but follow the rest of those steps.

Additional material about this topic is available for reading. (This is optional reading, and not a set of instructions that people are expected to follow when following this guide.) traffic forwarding