1This module matches packets related to a specific conntrack-helper. 2.TP 3.BI "--helper " "string" 4Matches packets related to the specified conntrack-helper. 5.RS 6.PP 7string can be "ftp" for packets related to a ftp-session on default port. 8For other ports append -portnr to the value, ie. "ftp-2121". 9.PP 10Same rules apply for other conntrack-helpers. 11.RE 12