IDENTPROTO Define this as 1 to get IDENT (RFC 1413) protocol support. This is assumed unless you are running on Ultrix or HP-UX, both of which have a problem in the UDP implementation. You can define it to be 0 to explicitly turn off IDENT protocol support. If defined off, the code is actually still compiled in, but it defaults off; you can turn it on by setting the IDENT timeout in the configuration file.
従って、全く逆に O Timeout.ident=5s とあるところを、 O Timeout.ident=0s にすれば切れるんでないかと..やったことないけどさ