permitremoteopen="60001"

in sshd_config PermitRemoteOpen

Specifies the permitted remote TCP port forwardin. The forwarding specification must be one of the following forms:

** PermitRemoteOpen port**

Multiple remote forwards may be specified by separating them with white space. An argument of any'' can be used to remove all restrictions and permit any forwarding requests. An argument of none'' can be used to prohibit all forwarding requests. By default all port forwarding requests are permitted.

in ~/.ssh/authorized_keys permitremoteopen="port"**

Limit local ``ssh -R'' port forwarding such that it may only forward the specified port. Multiple permitremteopen options may be applied separated by commas.