1This is used to send back an error packet in response to the matched
2packet: otherwise it is equivalent to
3.B DROP
4so it is a terminating TARGET, ending rule traversal.
5This target is only valid in the
6.BR INPUT ,
7.B FORWARD
8and
9.B OUTPUT
10chains, and user-defined chains which are only called from those
11chains.  The following option controls the nature of the error packet
12returned:
13.TP
14\fB\-\-reject\-with\fP \fItype\fP
15The type given can be
16\fBicmp6\-no\-route\fP,
17\fBno\-route\fP,
18\fBicmp6\-adm\-prohibited\fP,
19\fBadm\-prohibited\fP,
20\fBicmp6\-addr\-unreachable\fP,
21\fBaddr\-unreach\fP,
22\fBicmp6\-port\-unreachable\fP or
23\fBport\-unreach\fP
24which return the appropriate ICMPv6 error message (\fBport\-unreach\fP is
25the default). Finally, the option
26\fBtcp\-reset\fP
27can be used on rules which only match the TCP protocol: this causes a
28TCP RST packet to be sent back.  This is mainly useful for blocking
29.I ident
30(113/tcp) probes which frequently occur when sending mail to broken mail
31hosts (which won't accept your mail otherwise).
32\fBtcp\-reset\fP
33can only be used with kernel versions 2.6.14 or later.
34