Update Ports Collection

The stuff under /usr/ports is referred as Ports Collection, and we can employ portsnap command to update it:

(1) If it is the first time to use portsnap, you should run following command:

# portsnap fetch extract

Otherwise, you can encounter errors as shown here:

......
/usr/ports was not created by portsnap.
You must run 'portsnap extract' before running 'portsnap update'.

(2) Hereafter, you only need to execute "portsnap fetch update" to update the Ports Collection.

Reference:
Using the Ports Collection;
A question about using portsnanp to upgrade ports tree.