pfSense

Trying to telnet to a NATted server gives the following error:

xx@xx:~$ telnet xxx.xx 2201
Trying xx.xx.xx.xx...
Connected to xxx.xx.
Escape character is '^]'.
usage: nc [-46DdEhklnrStUuvz] [-e policy] [-I length] [-i interval] [-O length]
[-P proxy_username] [-p source_port] [-s source_ip_address] [-T ToS]
[-V fib] [-w timeout] [-X proxy_protocol]
[-x proxy_address[:port]] [hostname] [port]

SSH to the same server is working. NAT and rules for SSH and my other service on port 2201 is setup exactly the same, except for the port numbers and usage of aliases for the other service.