For security reasons, you might opt to log telnet and FTP sessions. On my box, those sessions are logged into the /var/adm/messages file. To make this change, you will have to modify the /etc/rc2.d/S72inetsvc script. Here's an example.
Go to the bottom of this file and look for this line, /usr/sbin/inetd -s &
# vi /etc/rc2.d/S72inetsvc
...
/usr/sbin/inetd -s &
Change to /usr/sbin/inetd -s -t &
: wq!
You will have to recycle the inetd daemon.