FreeBSD by default runs three sets of periodic scripts that outputs a volume of information about your system's current state. The output of these scripts are sent to the root account's mailbox. If you are like me and have a number of FreeBSD servers, its a pain to go check this mailbox on each machine. Well here is an easy fix to send the output of the scripts to any email address.

In FreeBSD 6.2, you could add the polling option in /etc/rc.conf for a given interface or specify it manually when using ifconfig. This enabled device polling if you enabled it when recompiling your kernel. In FreeBSD 6.3 polling is no longer an option for ifconfig. So, make sure it is not specified in /etc/rc.conf for your network interfaces, otherwise when you restart, your network interfaces will not have an IP address set. Thus, leading to a rather annoying walk over to the server room.

When upgrading from FreeBSD 6.2 to FreeBSD 6.3 with freebsd-update (detailed here) and using a custom built kernel, there is one extra step to be fully upgraded. After you follow the three steps from the instructions and reboot for the second time, you will be unpleasantly surprised to see that you are still using a 6.2 kernel. In fact all you need to do now and go rebuild your customized kernel, install it and reboot. Now you will have a customized 6.3 kernel installed.

In FreeBSD 6.2 and later, the freebsd-update command allows you to update binaries of your base operating system.

It has four commands:

fetch - Inspects current system and downloads available needed updates.

options TCP_RESTRICT_RST

This option limits the number of RST TCP packets FreeBSD will make. Port scanners will typically look for RST packets for closed ports. Limiting the number or responses can slow down port scans. Also this can be used to protect from denial of service attacks. To enable this option add to your rc.conf:
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If you need to remount a in-use filesystem like / or /usr without rebooting the operating system, use the mount command with the -o remount option.

To remount the root partition using settings found in /etc/fstab.conf run:

PXEBoot Setup

• Mount the FreeBSD install CD.

  mount /cdrom
  

• Copy all the contents of the FreeBSD install CD to /usr/tftpboot

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One complaint I've always had about FreeBSD port's tree is upgrading outdated installed ports. Typically you need to go by hand and uninstall all the dependancies of a port, upgrade the port, and then reinstall all the dependancies. However, there are a few solutions for port upgrade management. The one I like the best is portupgrade that is available in the ports tree under /usr/ports/sysutils/portupgrade.

Introduction

This HOWTO explains how to use OpenVPN for a IPv6 tunnel. This has only been tested on FreeBSD 7 as the server, and Mac OS X 10.5 as the client. It explicitly used the Gif interface that likely doesn't exist on other platforms.