Well, at this point all I can tell is I did this on an F25 VM that I have....
1. dnf install dictd-server
2. systemctl enable dictd
3. systemctl start dictd
And, FWIW...
[root@f25f ~]# telnet localhost 2628
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 f25f dictd 1.12.1/rf on Linux 4.8.11-300.fc25.x86_64 <auth.mime> <1.5487.1481263254@f25f>
quit
221 bye [d/m/c = 0/0/0; 4.000r 0.000u 0.000s]
So, I'm guessing at this point there is something in your configuration file or something
else you did to get the failure.