1This target is only valid in the
2.B nat
3table, in the
4.B POSTROUTING
5chain.  It specifies that the source address of the packet should be
6modified (and all future packets in this connection will also be
7mangled), and rules should cease being examined.  It takes one type
8of option:
9.TP
10.BR "--to-source  " "\fIipaddr\fP[-\fIipaddr\fP][:\fIport\fP-\fIport\fP]"
11which can specify a single new source IP address, an inclusive range
12of IP addresses, and optionally, a port range (which is only valid if
13the rule also specifies
14.B "-p tcp"
15or
16.BR "-p udp" ).
17If no port range is specified, then source ports below 512 will be
18mapped to other ports below 512: those between 512 and 1023 inclusive
19will be mapped to ports below 1024, and other ports will be mapped to
201024 or above. Where possible, no port alteration will
21
22In Kernels up to 2.6.10, you can add several --to-source options.  For those
23kernels, if you specify more than one source address, either via an address
24range or multiple --to-source options, a simple round-robin (one after another
25in cycle) takes place between these addresses.
26Later Kernels (>= 2.6.11-rc1) don't have the ability to NAT to multiple ranges
27anymore.
28.TP
29.BR "--random"
30If option
31.B "--random"
32is used then port mapping will be randomized (kernel >= 2.6.21).
33.RS
34.PP
35