Updating FreeBSD server system is quite easy. You can apply security patch to keep freebsd system up to date.

Required tools aka software

You need to have following tools on system
(a) portmanager – FreeBSD ultimate ports update utility.

(b) portsnap – It is a system for securely distributing the FreeBSD ports tree. Approximately once an hour, a snapshot of the ports tree is generated, repackaged, and cryptographically signed. The resulting files are then distributed via HTTP.

(c) pkg_version – List the installed version of the package is older than the current version.

All of the above utilities work together to keeping FreeBSD up to date 🙂

FreeBSD install portsnap (for older system version <6.0)

On FreeBSD 6.0+, portsnap is contained in the FreeBSD base (core) system. You only need to to install portsanp as follows for older FreeBSD system:
# cd /usr/ports/ports-mgmt/portsnap
# make install clean

FreeBSD install portmanager

Simply type the following command:
# cd /usr/ports/ports-mgmt/portmanager
# make install clean

Upgrade FreeBSD ports collection

Run portsnap as follows:
# portsnap fetch extract
OR
# portsnap fetch
# portsnap extract
Output:

Looking up portsnap.FreeBSD.org mirrors... 4 mirrors found.
Fetching public key from portsnap3.FreeBSD.org... done.
Fetching snapshot tag from portsnap3.FreeBSD.org... done.
Fetching snapshot metadata... done.
Fetching snapshot generated at Sun Aug  5 19:38:18 CDT 2007:
b73e908500446b6593a4f763b8b2128490e733547cdaa7100% of   49 MB  195 kBps 00m00s
Extracting snapshot... done.
Verifying snapshot integrity... done.
Fetching snapshot tag from portsnap3.FreeBSD.org... done.
Fetching snapshot metadata... done.
Updating from Sun Aug  5 19:38:18 CDT 2007 to Mon Aug  6 05:58:34 CDT 2007.
Fetching 4 metadata patches... done.
Applying metadata patches... done.
Fetching 0 metadata files... done.
Fetching 18 patches.....10.... done.
Applying patches... done.
Fetching 0 new ports or files... done.
....
..
...

Display outdated ports list

You can list outdated ports list with pkg_version command:
# pkg_version -vIL=
OR
# pkg_version -vIL'<'
Output:

bash-3.1.17                         <   needs updating (index has 3.2.17_2)
gettext-0.14.5_2                    <   needs updating (index has 0.16.1_3)
libtool-1.5.22_2                    <   needs updating (index has 1.5.22_4)
linux_base-fc-4_9                   <   needs updating (index has 4_10)
....
......
.

Where,

• v : Enable verbose output.
• I : Use only the index file for determining if a package is out of date (faster result)
• L= : Limit the output to those packages whose status flag does not match = (the installed version of the package is current.)
• L'<' : Limit the output to those packages whose status flag does not match < (the installed version of the package is older than the current version.)

Update FreeBSD packages / software

Now run portmanager to upgrade installed ports:
# portmanager -u

It will updates ports in the correct order based on their dependencies. If a port fails to "make" during update it is marked as ignored. Portmanager will continue updating any ports not marked as "ignored" so long as they are not dependent on the ignored port. Also note that it may take some time if you have large number of application installed.

If you need to upgrade all installed ports with logging, enter:
# portmanager -u -l

How do I upgrade a single software only?

portmanager allows you to update a single port and all of its dependencies. For example update port called bash i.e. bash shell (shells/bash), enter:
# portmanager shells/bash -l -u -f

How do I apply update again?

In order to update system again just type the following command:
# portsnap fetch
# portsnap update
# portmanager -u -l

How do I apply binary security updates for FreeBSD?

Latest version includes a tool called freebsd-update (thanks to Bok for pointing out this tool). The freebsd-update tool is used to fetch, install, and rollback binary updates to the FreeBSD base system.

Fetch updates

Use fetch option to get all available binary updates:
# freebsd-update fetch
Output:

Looking up update.FreeBSD.org mirrors... 1 mirrors found.
Fetching public key from update1.FreeBSD.org... done.
Fetching metadata signature from update1.FreeBSD.org... done.
Fetching metadata index... done.
Fetching 2 metadata files... done.
Inspecting system... done.
Preparing to download files... done.
Fetching 18 patches.....10.... done.
Applying patches... done.

The following files will be updated as part of updating to 6.2-RELEASE-p7:
/boot/kernel/kernel
/etc/rc.d/jail
....
.....
/usr/lib/libmagic.so.2
/usr/sbin/dnssec-signzone
/usr/sbin/freebsd-update
/usr/sbin/lwresd
/usr/sbin/named
/usr/sbin/named-checkconf
/usr/sbin/named-checkzone
/usr/sbin/tcpdump

WARNING: FreeBSD 6.2-RELEASE is approaching its End-of-Life date.
It is strongly recommended that you upgrade to a newer
release within the next 5 months.

Install updates

Install the most recently fetched updates:
# freebsd-update install
Output:

Installing updates... done.

Rollback updates

Optional: You can uninstall most recently installed updates:

# freebsd-update  rollback  

Reboot system

You must reboot FreeBSD to take advntage of newly patched kernel:
$ uname -a
Output:

FreeBSD vip-1.freebsd.nixcraft.com 6.2-RELEASE FreeBSD 6.2-RELEASE #0: Fri Jan 12 10:40:27 UTC 2007
root@dessler.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386

$ sudo reboot
After reboot verify system:
$ uname -a
Output:

FreeBSD vip-1.freebsd.nixcraft.com 6.2-RELEASE-p4 FreeBSD 6.2-RELEASE-p4 #0: Thu Apr 26 17:40:53 UTC 2007     root@i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  i386

Further readings:

• Read pkg_version, portmanager and portsnap man page
• Using Portsnap

Updated for accuracy.