To install memcached on freebsd simply follow steps below.

cd /usr/ports/databases/memcached
make install clean

After installation we need to activate it in rc.conf.

| /etc/rc.conf

memcached_enable="YES"
memcached_flags="-m 256 -l 127.0.0.1 -p 11211"
memcached_user="xyz"

Above code break down in following way.

-m : memory you want to allocate.
-l : address you want to listen on. - specify external ip if you want to centralize memcache between few server.
-p : specify ports for the memcached
-u : User as owner of memcached process

Testin memcached status.

echo stats | nc 127.0.0.1 11211

You are good to go.