This target is only valid in the \fBmangle\fR table, in the \fBPREROUTING\fR chain and user-defined chains which are only called from this chain. It redirects the packet to a local socket without changing the packet header in any way. It can also change the mark value which can then be used in advanced routing rules. It takes three options: .TP \fB--on-port\fR \fIport\fR This specifies a destination port to use. It is a required option, 0 means the new destination port is the same as the original. This is only valid if the rule also specifies \fB-p tcp\fR or \fB-p udp\fR. .TP \fB--on-ip\fR \fIaddress\fR This specifies a destination address to use. By default the address is the IP address of the incoming interface. This is only valid if the rule also specifies \fB-p tcp\fR or \fR-p udp\fR. .TP \fB--tproxy-mark\fR \fIvalue\fR[\fB/\fR\fImask\fR] Marks packets with the given value/mask. The fwmark value set here can be used by advanced routing. (Required for transparent proxying to work: otherwise these packets will get forwarded, which is probably not what you want.)