the connection does not  complete successfully.

no messages arrive after adding IP to AllowedIPAddresses list 

i tried adding all the sending IP addresses (including the ones i want to filter out) just to see if for some reason me touching  the setting caused the problem, and it that works ok.

when i remove one of the sending IP addresses from the list and receive a message from a IP not in the list. i see "Rejected connection attempt on port ...."  in the log and then  the above error.

Thanks

Thanks David,

There is no chance the source will correct their side

so will use second resolution:

should this do the job?

Class Test.BS.HL7.DMS.TCPService Extends EnsLib.HL7.Service.TCPService
{

/// Return the segment terminator string that the Parser and the document.ImportFromIOStream() method will use.
Method GetSegmentTerminator() As %String
{
    Quit $C(28,13,11)
}

Parameter ADAPTER = "Test.Adapter.HL7.DMS.TCPInboundAdapter";

}