Prepare FreeBSD

Enable IP Forwarding in the Kernel

If you have not already done so, enable IP forwarding in the kernel:

# sysctl net.inet.ip.forwarding=1
# sysctl net.inet.ip.fastforwarding=1
# sysctl net.inet6.ip6.forwarding=1

Make sure that the following lines exist in /etc/sysctl.conf so that the next time you reboot, IP forwarding is enabled by default:

# /etc/sysctl.conf
net.inet.ip.forwarding=1
net.inet.ip.fastforwarding=1
net.inet6.ip6.forwarding=1

Enable HTTP Accept Filter

Next, make sure that the HTTP Accept filter is loaded into the kernel.  You can check this by running the following command:

# kldstat
2    1 0xc0b12000 2464     accf_http.ko

If the filter is not loaded, edit /boot/loader.conf and add the following line so that when you reboot, the HTTP Accept filter kernel module is loaded.

# /boot/loader.conf
accf_http_load="YES"

Last of all, to load the module immediately, run the following command:

# kldload accf_http

System V Shared Memory and Semaphore Parameters

Modify System V shared memory and semaphore parameters

# sysctl kern.ipc.shmall=32768
# sysctl kern.ipc.shmmax=134217728
# sysctl kern.ipc.semmap=256

Once again, make these changes permanent by adding the following to /etc/sysctl.conf

# /etc/sysctl.conf
kern.ipc.shmall=32768
kern.ipc.shmmax=134217728
kern.ipc.semmap=256
net.inet.ip.forwarding=1
net.inet.ip.fastforwarding=1
net.inet6.ip6.forwarding=1

System V "Read-Only" Semaphore Parameters

Modify the System V "Read-Only" Semaphore Parameters by adding the following to /boot/loader.conf

NOTE: You must reboot for the new values of these parameters to take effect

# /boot/loader.conf
kern.ipc.semmni=256
kern.ipc.semmns=512
kern.ipc.semmnu=256
accf_http_load="YES"