| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | This target is only valid in the |
| 2 | .B nat |
| 3 | table, in the |
| 4 | .B POSTROUTING |
| 5 | chain. It specifies that the source address of the packet should be |
| 6 | modified (and all future packets in this connection will also be |
| 7 | mangled), and rules should cease being examined. It takes one type |
| 8 | of option: |
| 9 | .TP |
| 10 | \fB\-\-to\-source\fP \fIipaddr\fP[\fB\-\fP\fIipaddr\fP][\fB:\fP\fIport\fP[\fB\-\fP\fIport\fP]] |
| 11 | which can specify a single new source IP address, an inclusive range |
| 12 | of IP addresses, and optionally, a port range (which is only valid if |
| 13 | the rule also specifies |
| 14 | \fB\-p tcp\fP |
| 15 | or |
| 16 | \fB\-p udp\fP). |
| 17 | If no port range is specified, then source ports below 512 will be |
| 18 | mapped to other ports below 512: those between 512 and 1023 inclusive |
| 19 | will be mapped to ports below 1024, and other ports will be mapped to |
| 20 | 1024 or above. Where possible, no port alteration will |
| 21 | |
| 22 | In Kernels up to 2.6.10, you can add several \-\-to\-source options. For those |
| 23 | kernels, if you specify more than one source address, either via an address |
| 24 | range or multiple \-\-to\-source options, a simple round-robin (one after another |
| 25 | in cycle) takes place between these addresses. |
| 26 | Later Kernels (>= 2.6.11-rc1) don't have the ability to NAT to multiple ranges |
| 27 | anymore. |
| 28 | .TP |
| 29 | \fB\-\-random\fP |
| 30 | If option |
| 31 | \fB\-\-random\fP |
| 32 | is used then port mapping will be randomized (kernel >= 2.6.21). |
| 33 | .RS |
| 34 | .PP |