kazulog@sv1:~$ cat /etc/os-release | head -2
PRETTY_NAME="Ubuntu 26.04 LTS"
NAME="Ubuntu"
kazulog@sv1:~$ sudo update-inetd --enable telnet
kazulog@sv1:~$ grep -n telnet /etc/inetd.conf
23:telnet	stream	tcp	nowait	root	/usr/sbin/tcpd	/usr/sbin/telnetd
kazulog@sv1:~$ systemctl is-active inetutils-inetd
active
kazulog@sv1:~$ sudo ss -tlnp 'sport = :23'
State              Recv-Q             Send-Q                          Local Address:Port                           Peer Address:Port             Process
LISTEN             0                  10                                    0.0.0.0:23                                  0.0.0.0:*                 users:(("inetutils-inetd",pid=3120,fd=4))