Telnetd: All network ports in use

 

Count the number of ptys in /dev dir:

# ls /dev/pty* | wc -l

and you'll see you've reached the limit. To add new ones, do this:

# cd /dev
# ./MAKEDEV pty

where N is a number corresponding to the pty batch:

0 = ptyp0...ptypf
1 = ptyq0...ptyqf

 

Most likely an increase in concurrent users logged in.
You can use finger(1) to determine who is currently logged on and on which
terminal. You could run "finger | grep -v "Login" | wc -l" to find the total
number of pseudo terminals in use (including console).

To check total number of pseudo terminals available use
"ls /dev | grep pty | wc -l"